18718793 has 2 divisors, whose sum is σ = 18718794. Its totient is φ = 18718792.

The previous prime is 18718787. The next prime is 18718801. The reversal of 18718793 is 39781781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15578809 + 3139984 = 3947^2 + 1772^2 .

It is a cyclic number.

It is not a de Polignac number, because 18718793 - 2⁶ = 18718729 is a prime.

It is a super-2 number, since 2×18718793² = 700786422753698, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18718723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9359396 + 9359397.

It is an arithmetic number, because the mean of its divisors is an integer number (9359397).

Almost surely, 2^18718793 is an apocalyptic number.

It is an amenable number.

18718793 is a deficient number, since it is larger than the sum of its proper divisors (1).

18718793 is an equidigital number, since it uses as much as digits as its factorization.

18718793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 44.

The square root of 18718793 is about 4326.5220443215. The cubic root of 18718793 is about 265.5171720681.

The spelling of 18718793 in words is "eighteen million, seven hundred eighteen thousand, seven hundred ninety-three".