18557819 has 12 divisors (see below), whose sum is σ = 21803184. Its totient is φ = 15747984.

The previous prime is 18557807. The next prime is 18557821. The reversal of 18557819 is 91875581.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-18557819 is a prime.

It is a super-2 number, since 2×18557819² = 688785292073522, which contains 22 as substring.

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 18557819.

It is not an unprimeable number, because it can be changed into a prime (18557839) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3209 + ... + 6885.

It is an arithmetic number, because the mean of its divisors is an integer number (1816932).

Almost surely, 2^18557819 is an apocalyptic number.

18557819 is a deficient number, since it is larger than the sum of its proper divisors (3245365).

18557819 is a wasteful number, since it uses less digits than its factorization.

18557819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3794 (or 3787 counting only the distinct ones).

The product of its digits is 100800, while the sum is 44.

The square root of 18557819 is about 4307.8787123131. The cubic root of 18557819 is about 264.7538666311.

The spelling of 18557819 in words is "eighteen million, five hundred fifty-seven thousand, eight hundred nineteen".