18356747931 has 8 divisors (see below), whose sum is σ = 27195182160. Its totient is φ = 12237831936.

The previous prime is 18356747923. The next prime is 18356747933. The reversal of 18356747931 is 13974765381.

18356747931 is a `hidden beast` number, since 1 + 8 + 3 + 567 + 4 + 79 + 3 + 1 = 666.

It is not a de Polignac number, because 18356747931 - 2³ = 18356747923 is a prime.

It is a super-2 number, since 2×18356747931² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18356747933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 339939750 + ... + 339939803.

It is an arithmetic number, because the mean of its divisors is an integer number (3399397770).

Almost surely, 2^18356747931 is an apocalyptic number.

18356747931 is a deficient number, since it is larger than the sum of its proper divisors (8838434229).

18356747931 is an equidigital number, since it uses as much as digits as its factorization.

18356747931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679879562 (or 679879556 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 54.

The spelling of 18356747931 in words is "eighteen billion, three hundred fifty-six million, seven hundred forty-seven thousand, nine hundred thirty-one".