21102553560 has 128 divisors (see below), whose sum is σ = 73125504000. Its totient is φ = 4814837760.

The previous prime is 21102553559. The next prime is 21102553573. The reversal of 21102553560 is 6535520112.

It is a happy number.

It is a super-3 number, since 3×21102553560³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 447760 + ... + 492639.

It is an arithmetic number, because the mean of its divisors is an integer number (571293000).

Almost surely, 2^21102553560 is an apocalyptic number.

21102553560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102553560 is an abundant number, since it is smaller than the sum of its proper divisors (52022950440).

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

21102553560 is a wasteful number, since it uses less digits than its factorization.

21102553560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940441 (or 940437 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 21102553560 in words is "twenty-one billion, one hundred two million, five hundred fifty-three thousand, five hundred sixty".