21739915580 has 12 divisors (see below), whose sum is σ = 45653822760. Its totient is φ = 8695966224.

The previous prime is 21739915573. The next prime is 21739915591. The reversal of 21739915580 is 8551993712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 543497870 + ... + 543497909.

It is an arithmetic number, because the mean of its divisors is an integer number (3804485230).

Almost surely, 2^21739915580 is an apocalyptic number.

21739915580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21739915580 is an abundant number, since it is smaller than the sum of its proper divisors (23913907180).

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

21739915580 is a wasteful number, since it uses less digits than its factorization.

21739915580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086995788 (or 1086995786 counting only the distinct ones).

The product of its (nonzero) digits is 680400, while the sum is 50.

The spelling of 21739915580 in words is "twenty-one billion, seven hundred thirty-nine million, nine hundred fifteen thousand, five hundred eighty".