18136913 has 4 divisors (see below), whose sum is σ = 18161508. Its totient is φ = 18112320.

The previous prime is 18136907. The next prime is 18136931. The reversal of 18136913 is 31963181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31963181 = 199 ⋅160619.

It can be written as a sum of positive squares in 2 ways, for example, as 6385729 + 11751184 = 2527^2 + 3428^2 .

It is a cyclic number.

It is not a de Polignac number, because 18136913 - 2⁴ = 18136897 is a prime.

It is a super-2 number, since 2×18136913² = 657895226339138, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18136913.

It is not an unprimeable number, because it can be changed into a prime (18136933) 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 in 3 ways as a sum of consecutive naturals, for example, 11156 + ... + 12677.

It is an arithmetic number, because the mean of its divisors is an integer number (4540377).

Almost surely, 2^18136913 is an apocalyptic number.

It is an amenable number.

18136913 is a deficient number, since it is larger than the sum of its proper divisors (24595).

18136913 is an equidigital number, since it uses as much as digits as its factorization.

18136913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24594.

The product of its digits is 3888, while the sum is 32.

The square root of 18136913 is about 4258.7454725541. The cubic root of 18136913 is about 262.7369313583.

The spelling of 18136913 in words is "eighteen million, one hundred thirty-six thousand, nine hundred thirteen".