21512311300 has 72 divisors (see below), whose sum is σ = 47393966592. Its totient is φ = 8473920000.

The previous prime is 21512311237. The next prime is 21512311319. The reversal of 21512311300 is 311321512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11025325 + ... + 11027275.

It is an arithmetic number, because the mean of its divisors is an integer number (658249536).

Almost surely, 2^21512311300 is an apocalyptic number.

21512311300 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 21512311300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23696983296).

21512311300 is an abundant number, since it is smaller than the sum of its proper divisors (25881655292).

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

21512311300 is a wasteful number, since it uses less digits than its factorization.

21512311300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3589 (or 3582 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

Adding to 21512311300 its reverse (311321512), we get a palindrome (21823632812).

The spelling of 21512311300 in words is "twenty-one billion, five hundred twelve million, three hundred eleven thousand, three hundred".