21021212312320 has 288 divisors, whose sum is σ = 56842968913920. Its totient is φ = 7378024120320.

The previous prime is 21021212312311. The next prime is 21021212312329. The reversal of 21021212312320 is 2321321212012.

It is an interprime number because it is at equal distance from previous prime (21021212312311) and next prime (21021212312329).

It is a super-2 number, since 2×21021212312320² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21021212312291 and 21021212312300.

It is not an unprimeable number, because it can be changed into a prime (21021212312329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1577333497 + ... + 1577346823.

It is an arithmetic number, because the mean of its divisors is an integer number (197371419840).

Almost surely, 2^{21021212312320} is an apocalyptic number.

21021212312320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021212312320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28421484456960).

21021212312320 is an abundant number, since it is smaller than the sum of its proper divisors (35821756601600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21021212312320 is a wasteful number, since it uses less digits than its factorization.

21021212312320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17251 (or 17237 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 21021212312320 its reverse (2321321212012), we get a palindrome (23342533524332).

The spelling of 21021212312320 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, three hundred twelve thousand, three hundred twenty".