19918186977 has 16 divisors (see below), whose sum is σ = 28613139968. Its totient is φ = 12251917440.

The previous prime is 19918186931. The next prime is 19918186987. The reversal of 19918186977 is 77968181991.

It is not a de Polignac number, because 19918186977 - 2⁸ = 19918186721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19918186987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22993 + ... + 200910.

It is an arithmetic number, because the mean of its divisors is an integer number (1788321248).

Almost surely, 2^19918186977 is an apocalyptic number.

It is an amenable number.

19918186977 is a deficient number, since it is larger than the sum of its proper divisors (8694952991).

19918186977 is a wasteful number, since it uses less digits than its factorization.

19918186977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226200.

The product of its digits is 13716864, while the sum is 66.

The spelling of 19918186977 in words is "nineteen billion, nine hundred eighteen million, one hundred eighty-six thousand, nine hundred seventy-seven".