18625813 has 4 divisors (see below), whose sum is σ = 18643948. Its totient is φ = 18607680.

The previous prime is 18625793. The next prime is 18625819. The reversal of 18625813 is 31852681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31852681 = 7 ⋅4550383.

It can be written as a sum of positive squares in 2 ways, for example, as 17783089 + 842724 = 4217^2 + 918^2 .

It is a cyclic number.

It is not a de Polignac number, because 18625813 - 2¹⁷ = 18494741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18625819) 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, 7428 + ... + 9613.

It is an arithmetic number, because the mean of its divisors is an integer number (4660987).

Almost surely, 2^18625813 is an apocalyptic number.

It is an amenable number.

18625813 is a deficient number, since it is larger than the sum of its proper divisors (18135).

18625813 is a wasteful number, since it uses less digits than its factorization.

18625813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18134.

The product of its digits is 11520, while the sum is 34.

The square root of 18625813 is about 4315.7633160311. The cubic root of 18625813 is about 265.0768164634.

The spelling of 18625813 in words is "eighteen million, six hundred twenty-five thousand, eight hundred thirteen".