185981138 has 16 divisors (see below), whose sum is σ = 319006464. Its totient is φ = 79660800.

The previous prime is 185981137. The next prime is 185981161. The reversal of 185981138 is 831189581.

It is a happy number.

185981138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (185981137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36338 + ... + 41138.

It is an arithmetic number, because the mean of its divisors is an integer number (19937904).

Almost surely, 2^185981138 is an apocalyptic number.

185981138 is a deficient number, since it is larger than the sum of its proper divisors (133025326).

185981138 is a wasteful number, since it uses less digits than its factorization.

185981138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7577.

The product of its digits is 69120, while the sum is 44.

The square root of 185981138 is about 13637.4901649827. The cubic root of 185981138 is about 570.8074511054.

The spelling of 185981138 in words is "one hundred eighty-five million, nine hundred eighty-one thousand, one hundred thirty-eight".