21559659460 has 12 divisors (see below), whose sum is σ = 45275284908. Its totient is φ = 8623863776.

The previous prime is 21559659427. The next prime is 21559659467. The reversal of 21559659460 is 6495695512.

It can be written as a sum of positive squares in 2 ways, for example, as 3373518724 + 18186140736 = 58082^2 + 134856^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21559659398 and 21559659407.

It is not an unprimeable number, because it can be changed into a prime (21559659467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538991467 + ... + 538991506.

It is an arithmetic number, because the mean of its divisors is an integer number (3772940409).

Almost surely, 2^21559659460 is an apocalyptic number.

21559659460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21559659460 is an abundant number, since it is smaller than the sum of its proper divisors (23715625448).

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

21559659460 is a wasteful number, since it uses less digits than its factorization.

21559659460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077982982 (or 1077982980 counting only the distinct ones).

The product of its (nonzero) digits is 2916000, while the sum is 52.

The spelling of 21559659460 in words is "twenty-one billion, five hundred fifty-nine million, six hundred fifty-nine thousand, four hundred sixty".