21231321211320 has 128 divisors (see below), whose sum is σ = 69611354346240. Its totient is φ = 5137577303040.

The previous prime is 21231321211297. The next prime is 21231321211327. The reversal of 21231321211320 is 2311212313212.

It is a super-2 number, since 2×21231321211320² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231321211327) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13980277 + ... + 15424356.

It is an arithmetic number, because the mean of its divisors is an integer number (543838705830).

Almost surely, 2^{21231321211320} is an apocalyptic number.

21231321211320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231321211320 is an abundant number, since it is smaller than the sum of its proper divisors (48380033134920).

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

21231321211320 is a wasteful number, since it uses less digits than its factorization.

21231321211320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29405205 (or 29405201 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

Adding to 21231321211320 its reverse (2311212313212), we get a palindrome (23542533524532).

The spelling of 21231321211320 in words is "twenty-one trillion, two hundred thirty-one billion, three hundred twenty-one million, two hundred eleven thousand, three hundred twenty".