21037881688 has 32 divisors (see below), whose sum is σ = 40327243200. Its totient is φ = 10284416512.

The previous prime is 21037881679. The next prime is 21037881749. The reversal of 21037881688 is 88618873012.

It is a happy number.

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, 338718 + ... + 395986.

It is an arithmetic number, because the mean of its divisors is an integer number (1260226350).

Almost surely, 2^21037881688 is an apocalyptic number.

It is an amenable number.

21037881688 is a deficient number, since it is larger than the sum of its proper divisors (19289361512).

21037881688 is a wasteful number, since it uses less digits than its factorization.

21037881688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58299 (or 58295 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 52.

The spelling of 21037881688 in words is "twenty-one billion, thirty-seven million, eight hundred eighty-one thousand, six hundred eighty-eight".