18645952891 has 2 divisors, whose sum is σ = 18645952892. Its totient is φ = 18645952890.

The previous prime is 18645952883. The next prime is 18645952909. The reversal of 18645952891 is 19825954681.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18645952891 - 2³ = 18645952883 is a prime.

It is not a weakly prime, because it can be changed into another prime (18645952691) 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, 9322976445 + 9322976446.

It is an arithmetic number, because the mean of its divisors is an integer number (9322976446).

Almost surely, 2^18645952891 is an apocalyptic number.

18645952891 is a deficient number, since it is larger than the sum of its proper divisors (1).

18645952891 is an equidigital number, since it uses as much as digits as its factorization.

18645952891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6220800, while the sum is 58.

The spelling of 18645952891 in words is "eighteen billion, six hundred forty-five million, nine hundred fifty-two thousand, eight hundred ninety-one".