18949399451 has 2 divisors, whose sum is σ = 18949399452. Its totient is φ = 18949399450.

The previous prime is 18949399423. The next prime is 18949399463. The reversal of 18949399451 is 15499394981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18949399451 - 2²⁶ = 18882290587 is a prime.

It is not a weakly prime, because it can be changed into another prime (18949390451) 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, 9474699725 + 9474699726.

It is an arithmetic number, because the mean of its divisors is an integer number (9474699726).

Almost surely, 2^18949399451 is an apocalyptic number.

18949399451 is a deficient number, since it is larger than the sum of its proper divisors (1).

18949399451 is an equidigital number, since it uses as much as digits as its factorization.

18949399451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12597120, while the sum is 62.

The spelling of 18949399451 in words is "eighteen billion, nine hundred forty-nine million, three hundred ninety-nine thousand, four hundred fifty-one".