18798887 has 4 divisors (see below), whose sum is σ = 19056480. Its totient is φ = 18541296.

The previous prime is 18798881. The next prime is 18798907. The reversal of 18798887 is 78889781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78889781 = 41 ⋅1924141.

It is a cyclic number.

It is not a de Polignac number, because 18798887 - 2¹⁴ = 18782503 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 (18798881) 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, 128687 + ... + 128832.

It is an arithmetic number, because the mean of its divisors is an integer number (4764120).

Almost surely, 2^18798887 is an apocalyptic number.

18798887 is a deficient number, since it is larger than the sum of its proper divisors (257593).

18798887 is an equidigital number, since it uses as much as digits as its factorization.

18798887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257592.

The product of its digits is 1806336, while the sum is 56.

The square root of 18798887 is about 4335.7683286818. The cubic root of 18798887 is about 265.8953316500.

The spelling of 18798887 in words is "eighteen million, seven hundred ninety-eight thousand, eight hundred eighty-seven".