21072107187 has 12 divisors (see below), whose sum is σ = 32039461480. Its totient is φ = 13308699168.

The previous prime is 21072107171. The next prime is 21072107191. The reversal of 21072107187 is 78170127012.

It is not a de Polignac number, because 21072107187 - 2⁴ = 21072107171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1072107187) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61614178 + ... + 61614519.

Almost surely, 2^21072107187 is an apocalyptic number.

21072107187 is a deficient number, since it is larger than the sum of its proper divisors (10967354293).

21072107187 is a wasteful number, since it uses less digits than its factorization.

21072107187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123228722 (or 123228719 counting only the distinct ones).

The product of its (nonzero) digits is 10976, while the sum is 36.

The spelling of 21072107187 in words is "twenty-one billion, seventy-two million, one hundred seven thousand, one hundred eighty-seven".