21121312300 has 108 divisors (see below), whose sum is σ = 50594718328. Its totient is φ = 7647552000.

The previous prime is 21121312283. The next prime is 21121312307. The reversal of 21121312300 is 321312112.

It is a super-2 number, since 2×21121312300² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121312307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2912479 + ... + 2919721.

Almost surely, 2^21121312300 is an apocalyptic number.

21121312300 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 21121312300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25297359164).

21121312300 is an abundant number, since it is smaller than the sum of its proper divisors (29473406028).

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

21121312300 is a wasteful number, since it uses less digits than its factorization.

21121312300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7520 (or 7502 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21121312300 its reverse (321312112), we get a palindrome (21442624412).

The spelling of 21121312300 in words is "twenty-one billion, one hundred twenty-one million, three hundred twelve thousand, three hundred".