21158137902 has 16 divisors (see below), whose sum is σ = 46163210112. Its totient is φ = 6411556920.

The previous prime is 21158137883. The next prime is 21158137921. The reversal of 21158137902 is 20973185112.

It is a happy number.

21158137902 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (21158137883) and next prime (21158137921).

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, 160288858 + ... + 160288989.

It is an arithmetic number, because the mean of its divisors is an integer number (2885200632).

Almost surely, 2^21158137902 is an apocalyptic number.

21158137902 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21158137902 is an abundant number, since it is smaller than the sum of its proper divisors (25005072210).

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

21158137902 is a wasteful number, since it uses less digits than its factorization.

21158137902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320577863.

The product of its (nonzero) digits is 30240, while the sum is 39.

The spelling of 21158137902 in words is "twenty-one billion, one hundred fifty-eight million, one hundred thirty-seven thousand, nine hundred two".