21138132015 has 96 divisors (see below), whose sum is σ = 49194302976. Its totient is φ = 8108916480.

The previous prime is 21138132007. The next prime is 21138132023. The reversal of 21138132015 is 51023183112.

It is an interprime number because it is at equal distance from previous prime (21138132007) and next prime (21138132023).

It is not a de Polignac number, because 21138132015 - 2³ = 21138132007 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21138132015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 189589 + ... + 279678.

It is an arithmetic number, because the mean of its divisors is an integer number (512440656).

Almost surely, 2^21138132015 is an apocalyptic number.

21138132015 is an abundant number, since it is smaller than the sum of its proper divisors (28056170961).

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

21138132015 is a wasteful number, since it uses less digits than its factorization.

21138132015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469309 (or 469306 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 21138132015 in words is "twenty-one billion, one hundred thirty-eight million, one hundred thirty-two thousand, fifteen".