18947794939 has 2 divisors, whose sum is σ = 18947794940. Its totient is φ = 18947794938.

The previous prime is 18947794919. The next prime is 18947794961. The reversal of 18947794939 is 93949774981.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18947794939 is a prime.

It is not a weakly prime, because it can be changed into another prime (18947794909) 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, 9473897469 + 9473897470.

It is an arithmetic number, because the mean of its divisors is an integer number (9473897470).

Almost surely, 2^18947794939 is an apocalyptic number.

18947794939 is a deficient number, since it is larger than the sum of its proper divisors (1).

18947794939 is an equidigital number, since it uses as much as digits as its factorization.

18947794939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 123451776, while the sum is 70.

The spelling of 18947794939 in words is "eighteen billion, nine hundred forty-seven million, seven hundred ninety-four thousand, nine hundred thirty-nine".