18356913 has 24 divisors (see below), whose sum is σ = 27903720. Its totient is φ = 11612160.

The previous prime is 18356909. The next prime is 18356917. The reversal of 18356913 is 31965381.

It is a happy number.

18356913 is a `hidden beast` number, since 1 + 83 + 569 + 13 = 666.

18356913 is nontrivially palindromic in base 13.

It is an interprime number because it is at equal distance from previous prime (18356909) and next prime (18356917).

It can be written as a sum of positive squares in 4 ways, for example, as 1192464 + 17164449 = 1092^2 + 4143^2 .

It is not a de Polignac number, because 18356913 - 2² = 18356909 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18356917) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15345 + ... + 16497.

It is an arithmetic number, because the mean of its divisors is an integer number (1162655).

Almost surely, 2^18356913 is an apocalyptic number.

It is an amenable number.

18356913 is a deficient number, since it is larger than the sum of its proper divisors (9546807).

18356913 is a wasteful number, since it uses less digits than its factorization.

18356913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249 (or 1246 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 18356913 is about 4284.4968199311. The cubic root of 18356913 is about 263.7949940833.

The spelling of 18356913 in words is "eighteen million, three hundred fifty-six thousand, nine hundred thirteen".