21640698960 has 40 divisors (see below), whose sum is σ = 67086167520. Its totient is φ = 5770852992.

The previous prime is 21640698899. The next prime is 21640698991. The reversal of 21640698960 is 6989604612.

It is a tau number, because it is divible by the number of its divisors (40).

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, 45084550 + ... + 45085029.

It is an arithmetic number, because the mean of its divisors is an integer number (1677154188).

Almost surely, 2^21640698960 is an apocalyptic number.

21640698960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21640698960 is an abundant number, since it is smaller than the sum of its proper divisors (45445468560).

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

21640698960 is a wasteful number, since it uses less digits than its factorization.

21640698960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90169595 (or 90169589 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 51.

It can be divided in two parts, 21640 and 698960, that added together give a triangular number (720600 = T₁₂₀₀).

The spelling of 21640698960 in words is "twenty-one billion, six hundred forty million, six hundred ninety-eight thousand, nine hundred sixty".