19918186931 has 2 divisors, whose sum is σ = 19918186932. Its totient is φ = 19918186930.

The previous prime is 19918186919. The next prime is 19918186987. The reversal of 19918186931 is 13968181991.

It is an a-pointer prime, because the next prime (19918186987) can be obtained adding 19918186931 to its sum of digits (56).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19918186931 - 2¹⁰ = 19918185907 is a prime.

It is a super-2 number, since 2×19918186931² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19918182931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9959093465 + 9959093466.

It is an arithmetic number, because the mean of its divisors is an integer number (9959093466).

Almost surely, 2^19918186931 is an apocalyptic number.

19918186931 is a deficient number, since it is larger than the sum of its proper divisors (1).

19918186931 is an equidigital number, since it uses as much as digits as its factorization.

19918186931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 56.

The spelling of 19918186931 in words is "nineteen billion, nine hundred eighteen million, one hundred eighty-six thousand, nine hundred thirty-one".