18389957 has 2 divisors, whose sum is σ = 18389958. Its totient is φ = 18389956.

The previous prime is 18389953. The next prime is 18389989. The reversal of 18389957 is 75998381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15570916 + 2819041 = 3946^2 + 1679^2 .

It is a cyclic number.

It is not a de Polignac number, because 18389957 - 2² = 18389953 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18389953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9194978 + 9194979.

It is an arithmetic number, because the mean of its divisors is an integer number (9194979).

Almost surely, 2^18389957 is an apocalyptic number.

It is an amenable number.

18389957 is a deficient number, since it is larger than the sum of its proper divisors (1).

18389957 is an equidigital number, since it uses as much as digits as its factorization.

18389957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 18389957 is about 4288.3513148995. The cubic root of 18389957 is about 263.9531836558.

The spelling of 18389957 in words is "eighteen million, three hundred eighty-nine thousand, nine hundred fifty-seven".