18550564978 has 16 divisors (see below), whose sum is σ = 30573859680. Its totient is φ = 8371411200.

The previous prime is 18550564957. The next prime is 18550564987. The reversal of 18550564978 is 87946505581.

It is a happy number.

It is a super-2 number, since 2×18550564978² (a number of 21 digits) contains 22 as substring.

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, 3030063 + ... + 3036178.

It is an arithmetic number, because the mean of its divisors is an integer number (1910866230).

Almost surely, 2^18550564978 is an apocalyptic number.

18550564978 is a deficient number, since it is larger than the sum of its proper divisors (12023294702).

18550564978 is a wasteful number, since it uses less digits than its factorization.

18550564978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6066393.

The product of its (nonzero) digits is 12096000, while the sum is 58.

The spelling of 18550564978 in words is "eighteen billion, five hundred fifty million, five hundred sixty-four thousand, nine hundred seventy-eight".