18991377323 has 2 divisors, whose sum is σ = 18991377324. Its totient is φ = 18991377322.

The previous prime is 18991377319. The next prime is 18991377337. The reversal of 18991377323 is 32377319981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18991377323 - 2² = 18991377319 is a prime.

It is not a weakly prime, because it can be changed into another prime (18991377313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9495688661 + 9495688662.

It is an arithmetic number, because the mean of its divisors is an integer number (9495688662).

Almost surely, 2^18991377323 is an apocalyptic number.

18991377323 is a deficient number, since it is larger than the sum of its proper divisors (1).

18991377323 is an equidigital number, since it uses as much as digits as its factorization.

18991377323 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1714608, while the sum is 53.

The spelling of 18991377323 in words is "eighteen billion, nine hundred ninety-one million, three hundred seventy-seven thousand, three hundred twenty-three".