21512653265200 has 30 divisors (see below), whose sum is σ = 51684149470604. Its totient is φ = 8605061305920.

The previous prime is 21512653265161. The next prime is 21512653265221. The reversal of 21512653265200 is 256235621512.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 26890816182 + ... + 26890816981.

Almost surely, 2^{21512653265200} is an apocalyptic number.

21512653265200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21512653265200 is an abundant number, since it is smaller than the sum of its proper divisors (30171496205404).

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

21512653265200 is a wasteful number, since it uses less digits than its factorization.

21512653265200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53781633181 (or 53781633170 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 40.

Adding to 21512653265200 its reverse (256235621512), we get a palindrome (21768888886712).

The spelling of 21512653265200 in words is "twenty-one trillion, five hundred twelve billion, six hundred fifty-three million, two hundred sixty-five thousand, two hundred".