18885861 has 36 divisors (see below), whose sum is σ = 29740932. Its totient is φ = 11541504.

The previous prime is 18885857. The next prime is 18885883. The reversal of 18885861 is 16858881.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3629025 + 15256836 = 1905^2 + 3906^2 .

It is not a de Polignac number, because 18885861 - 2² = 18885857 is a prime.

It is a super-2 number, since 2×18885861² = 713351491422642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18885961) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 137785 + ... + 137921.

It is an arithmetic number, because the mean of its divisors is an integer number (826137).

Almost surely, 2^18885861 is an apocalyptic number.

It is an amenable number.

18885861 is a deficient number, since it is larger than the sum of its proper divisors (10855071).

18885861 is a wasteful number, since it uses less digits than its factorization.

18885861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 210 counting only the distinct ones).

The product of its digits is 122880, while the sum is 45.

The square root of 18885861 is about 4345.7865801256. The cubic root of 18885861 is about 266.3047602766.

The spelling of 18885861 in words is "eighteen million, eight hundred eighty-five thousand, eight hundred sixty-one".