18931609402 has 8 divisors (see below), whose sum is σ = 28421834976. Its totient is φ = 9457664412.

The previous prime is 18931609349. The next prime is 18931609423. The reversal of 18931609402 is 20490613981.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 4067238 + ... + 4071889.

It is an arithmetic number, because the mean of its divisors is an integer number (3552729372).

Almost surely, 2^18931609402 is an apocalyptic number.

18931609402 is a deficient number, since it is larger than the sum of its proper divisors (9490225574).

18931609402 is a wasteful number, since it uses less digits than its factorization.

18931609402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8140292.

The product of its (nonzero) digits is 93312, while the sum is 43.

The spelling of 18931609402 in words is "eighteen billion, nine hundred thirty-one million, six hundred nine thousand, four hundred two".