18661395156 has 24 divisors (see below), whose sum is σ = 43564358880. Its totient is φ = 6217450272.

The previous prime is 18661395061. The next prime is 18661395173. The reversal of 18661395156 is 65159316681.

It is a junction number, because it is equal to n+sod(n) for n = 18661395099 and 18661395108.

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, 350986 + ... + 400641.

It is an arithmetic number, because the mean of its divisors is an integer number (1815181620).

Almost surely, 2^18661395156 is an apocalyptic number.

It is an amenable number.

18661395156 is an abundant number, since it is smaller than the sum of its proper divisors (24902963724).

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

18661395156 is a wasteful number, since it uses less digits than its factorization.

18661395156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753703 (or 753701 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 51.

The spelling of 18661395156 in words is "eighteen billion, six hundred sixty-one million, three hundred ninety-five thousand, one hundred fifty-six".