18949399423 has 2 divisors, whose sum is σ = 18949399424. Its totient is φ = 18949399422.

The previous prime is 18949399397. The next prime is 18949399451. The reversal of 18949399423 is 32499394981.

It is a weak prime.

It is an emirp because it is prime and its reverse (32499394981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18949399423 - 2²¹ = 18947302271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18949399463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9474699711 + 9474699712.

It is an arithmetic number, because the mean of its divisors is an integer number (9474699712).

Almost surely, 2^18949399423 is an apocalyptic number.

18949399423 is a deficient number, since it is larger than the sum of its proper divisors (1).

18949399423 is an equidigital number, since it uses as much as digits as its factorization.

18949399423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15116544, while the sum is 61.

The spelling of 18949399423 in words is "eighteen billion, nine hundred forty-nine million, three hundred ninety-nine thousand, four hundred twenty-three".