21102421560 has 64 divisors (see below), whose sum is σ = 69062474880. Its totient is φ = 5115738240.

The previous prime is 21102421559. The next prime is 21102421577. The reversal of 21102421560 is 6512420112.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21102421560.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7992022 + ... + 7994661.

It is an arithmetic number, because the mean of its divisors is an integer number (1079101170).

Almost surely, 2^21102421560 is an apocalyptic number.

21102421560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102421560 is an abundant number, since it is smaller than the sum of its proper divisors (47960053320).

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

21102421560 is a wasteful number, since it uses less digits than its factorization.

21102421560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15986708 (or 15986704 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

Adding to 21102421560 its reverse (6512420112), we get a palindrome (27614841672).

The spelling of 21102421560 in words is "twenty-one billion, one hundred two million, four hundred twenty-one thousand, five hundred sixty".