18690451979 has 2 divisors, whose sum is σ = 18690451980. Its totient is φ = 18690451978.

The previous prime is 18690451919. The next prime is 18690451999. The reversal of 18690451979 is 97915409681.

It is a strong prime.

It is an emirp because it is prime and its reverse (97915409681) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18690451979 is a prime.

It is not a weakly prime, because it can be changed into another prime (18690451919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9345225989 + 9345225990.

It is an arithmetic number, because the mean of its divisors is an integer number (9345225990).

Almost surely, 2^18690451979 is an apocalyptic number.

18690451979 is a deficient number, since it is larger than the sum of its proper divisors (1).

18690451979 is an equidigital number, since it uses as much as digits as its factorization.

18690451979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4898880, while the sum is 59.

The spelling of 18690451979 in words is "eighteen billion, six hundred ninety million, four hundred fifty-one thousand, nine hundred seventy-nine".