18408557 has 4 divisors (see below), whose sum is σ = 18434880. Its totient is φ = 18382236.

The previous prime is 18408547. The next prime is 18408571. The reversal of 18408557 is 75580481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18408557 - 2⁴ = 18408541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18408557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18408517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12083 + ... + 13520.

It is an arithmetic number, because the mean of its divisors is an integer number (4608720).

Almost surely, 2^18408557 is an apocalyptic number.

It is an amenable number.

18408557 is a deficient number, since it is larger than the sum of its proper divisors (26323).

18408557 is an equidigital number, since it uses as much as digits as its factorization.

18408557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26322.

The product of its (nonzero) digits is 44800, while the sum is 38.

The square root of 18408557 is about 4290.5194324231. The cubic root of 18408557 is about 264.0421429891.

The spelling of 18408557 in words is "eighteen million, four hundred eight thousand, five hundred fifty-seven".