21173878192 has 20 divisors (see below), whose sum is σ = 41095506376. Its totient is φ = 10568586240.

The previous prime is 21173878181. The next prime is 21173878241. The reversal of 21173878192 is 29187837112.

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, 1137534 + ... + 1155997.

Almost surely, 2^21173878192 is an apocalyptic number.

It is an amenable number.

21173878192 is a deficient number, since it is larger than the sum of its proper divisors (19921628184).

21173878192 is a wasteful number, since it uses less digits than its factorization.

21173878192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2294116 (or 2294110 counting only the distinct ones).

The product of its digits is 338688, while the sum is 49.

The spelling of 21173878192 in words is "twenty-one billion, one hundred seventy-three million, eight hundred seventy-eight thousand, one hundred ninety-two".