185811138 has 16 divisors (see below), whose sum is σ = 412913760. Its totient is φ = 61937028.

The previous prime is 185811113. The next prime is 185811191. The reversal of 185811138 is 831118581.

It is a happy number.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1720420 + ... + 1720527.

It is an arithmetic number, because the mean of its divisors is an integer number (25807110).

Almost surely, 2^185811138 is an apocalyptic number.

185811138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

185811138 is an abundant number, since it is smaller than the sum of its proper divisors (227102622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

185811138 is a wasteful number, since it uses less digits than its factorization.

185811138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3440958 (or 3440952 counting only the distinct ones).

The product of its digits is 7680, while the sum is 36.

The square root of 185811138 is about 13631.2559215943. The cubic root of 185811138 is about 570.6334785383.

It can be divided in two parts, 1858 and 11138, that added together give a square (12996 = 114²).

The spelling of 185811138 in words is "one hundred eighty-five million, eight hundred eleven thousand, one hundred thirty-eight".