18995557 has 4 divisors (see below), whose sum is σ = 21709216. Its totient is φ = 16281900.

The previous prime is 18995533. The next prime is 18995597. The reversal of 18995557 is 75559981.

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 18995557 - 2²³ = 10606949 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 18995557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18995507) 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, 1356819 + ... + 1356832.

It is an arithmetic number, because the mean of its divisors is an integer number (5427304).

Almost surely, 2^18995557 is an apocalyptic number.

It is an amenable number.

18995557 is a deficient number, since it is larger than the sum of its proper divisors (2713659).

18995557 is an equidigital number, since it uses as much as digits as its factorization.

18995557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2713658.

The product of its digits is 567000, while the sum is 49.

The square root of 18995557 is about 4358.3892666902. The cubic root of 18995557 is about 266.8193637621.

The spelling of 18995557 in words is "eighteen million, nine hundred ninety-five thousand, five hundred fifty-seven".