18851939 has 2 divisors, whose sum is σ = 18851940. Its totient is φ = 18851938.

The previous prime is 18851909. The next prime is 18851951. The reversal of 18851939 is 93915881.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18851939 - 2⁸ = 18851683 is a prime.

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 18851939.

It is not a weakly prime, because it can be changed into another prime (18851909) 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, 9425969 + 9425970.

It is an arithmetic number, because the mean of its divisors is an integer number (9425970).

Almost surely, 2^18851939 is an apocalyptic number.

18851939 is a deficient number, since it is larger than the sum of its proper divisors (1).

18851939 is an equidigital number, since it uses as much as digits as its factorization.

18851939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 44.

The square root of 18851939 is about 4341.8819652312. The cubic root of 18851939 is about 266.1452228662.

The spelling of 18851939 in words is "eighteen million, eight hundred fifty-one thousand, nine hundred thirty-nine".