18900913 has 4 divisors (see below), whose sum is σ = 19257588. Its totient is φ = 18544240.

The previous prime is 18900899. The next prime is 18900919. The reversal of 18900913 is 31900981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14992384 + 3908529 = 3872^2 + 1977^2 .

It is a cyclic number.

It is not a de Polignac number, because 18900913 - 2⁵ = 18900881 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18900919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178258 + ... + 178363.

It is an arithmetic number, because the mean of its divisors is an integer number (4814397).

Almost surely, 2^18900913 is an apocalyptic number.

It is an amenable number.

18900913 is a deficient number, since it is larger than the sum of its proper divisors (356675).

18900913 is an equidigital number, since it uses as much as digits as its factorization.

18900913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356674.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 18900913 is about 4347.5180275647. The cubic root of 18900913 is about 266.3754896408.

The spelling of 18900913 in words is "eighteen million, nine hundred thousand, nine hundred thirteen".