18943957 has 2 divisors, whose sum is σ = 18943958. Its totient is φ = 18943956.

The previous prime is 18943937. The next prime is 18943993. The reversal of 18943957 is 75934981.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18438436 + 505521 = 4294^2 + 711^2 .

It is an emirp because it is prime and its reverse (75934981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18943957 - 2⁷ = 18943829 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18943907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9471978 + 9471979.

It is an arithmetic number, because the mean of its divisors is an integer number (9471979).

Almost surely, 2^18943957 is an apocalyptic number.

It is an amenable number.

18943957 is a deficient number, since it is larger than the sum of its proper divisors (1).

18943957 is an equidigital number, since it uses as much as digits as its factorization.

18943957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 46.

The square root of 18943957 is about 4352.4656230693. The cubic root of 18943957 is about 266.5775464345.

It can be divided in two parts, 18943 and 957, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 18943957 in words is "eighteen million, nine hundred forty-three thousand, nine hundred fifty-seven".