18937979 has 2 divisors, whose sum is σ = 18937980. Its totient is φ = 18937978.

The previous prime is 18937973. The next prime is 18937981. The reversal of 18937979 is 97973981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18937979 - 2¹² = 18933883 is a prime.

Together with 18937981, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18937979.

It is not a weakly prime, because it can be changed into another prime (18937973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9468989 + 9468990.

It is an arithmetic number, because the mean of its divisors is an integer number (9468990).

Almost surely, 2^18937979 is an apocalyptic number.

18937979 is a deficient number, since it is larger than the sum of its proper divisors (1).

18937979 is an equidigital number, since it uses as much as digits as its factorization.

18937979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 857304, while the sum is 53.

The square root of 18937979 is about 4351.7788316963. The cubic root of 18937979 is about 266.5495028702.

The spelling of 18937979 in words is "eighteen million, nine hundred thirty-seven thousand, nine hundred seventy-nine".