18509779612 has 12 divisors (see below), whose sum is σ = 32406293920. Its totient is φ = 9250838496.

The previous prime is 18509779601. The next prime is 18509779633. The reversal of 18509779612 is 21697790581.

It is a happy number.

It is a super-2 number, since 2×18509779612² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 1002537 + ... + 1020832.

Almost surely, 2^18509779612 is an apocalyptic number.

It is an amenable number.

18509779612 is a deficient number, since it is larger than the sum of its proper divisors (13896514308).

18509779612 is a wasteful number, since it uses less digits than its factorization.

18509779612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2025660 (or 2025658 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 55.

The spelling of 18509779612 in words is "eighteen billion, five hundred nine million, seven hundred seventy-nine thousand, six hundred twelve".