21553731260 has 24 divisors (see below), whose sum is σ = 45293094000. Its totient is φ = 8615729024.

The previous prime is 21553731223. The next prime is 21553731307. The reversal of 21553731260 is 6213735512.

It is a self number, because there is not a number n which added to its sum of digits gives 21553731260.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 329489 + ... + 389448.

It is an arithmetic number, because the mean of its divisors is an integer number (1887212250).

Almost surely, 2^21553731260 is an apocalyptic number.

21553731260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21553731260 is an abundant number, since it is smaller than the sum of its proper divisors (23739362740).

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

21553731260 is a wasteful number, since it uses less digits than its factorization.

21553731260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720445 (or 720443 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 35.

The spelling of 21553731260 in words is "twenty-one billion, five hundred fifty-three million, seven hundred thirty-one thousand, two hundred sixty".