18977879 has 2 divisors, whose sum is σ = 18977880. Its totient is φ = 18977878.

The previous prime is 18977873. The next prime is 18977891. The reversal of 18977879 is 97877981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18977879 - 2⁴ = 18977863 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18977873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9488939 + 9488940.

It is an arithmetic number, because the mean of its divisors is an integer number (9488940).

Almost surely, 2^18977879 is an apocalyptic number.

18977879 is a deficient number, since it is larger than the sum of its proper divisors (1).

18977879 is an equidigital number, since it uses as much as digits as its factorization.

18977879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 56.

The square root of 18977879 is about 4356.3607518203. The cubic root of 18977879 is about 266.7365672658.

The spelling of 18977879 in words is "eighteen million, nine hundred seventy-seven thousand, eight hundred seventy-nine".