18998831 has 2 divisors, whose sum is σ = 18998832. Its totient is φ = 18998830.

The previous prime is 18998821. The next prime is 18998839. The reversal of 18998831 is 13889981.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18998831 is a prime.

It is a super-2 number, since 2×18998831² = 721911158733122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18998839) 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, 9499415 + 9499416.

It is an arithmetic number, because the mean of its divisors is an integer number (9499416).

Almost surely, 2^18998831 is an apocalyptic number.

18998831 is a deficient number, since it is larger than the sum of its proper divisors (1).

18998831 is an equidigital number, since it uses as much as digits as its factorization.

18998831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 47.

The square root of 18998831 is about 4358.7648479816. The cubic root of 18998831 is about 266.8346921959.

The spelling of 18998831 in words is "eighteen million, nine hundred ninety-eight thousand, eight hundred thirty-one".