18861386 has 4 divisors (see below), whose sum is σ = 28292082. Its totient is φ = 9430692.

The previous prime is 18861377. The next prime is 18861407. The reversal of 18861386 is 68316881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68316881 = 1297 ⋅52673.

It can be written as a sum of positive squares in only one way, i.e., 17480761 + 1380625 = 4181^2 + 1175^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4715345 + ... + 4715348.

Almost surely, 2^18861386 is an apocalyptic number.

18861386 is a deficient number, since it is larger than the sum of its proper divisors (9430696).

18861386 is an equidigital number, since it uses as much as digits as its factorization.

18861386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9430695.

The product of its digits is 55296, while the sum is 41.

The square root of 18861386 is about 4342.9697212852. The cubic root of 18861386 is about 266.1896719466.

The spelling of 18861386 in words is "eighteen million, eight hundred sixty-one thousand, three hundred eighty-six".