181938312 has 40 divisors (see below), whose sum is σ = 509597550. Its totient is φ = 60645888.

The previous prime is 181938307. The next prime is 181938313. The reversal of 181938312 is 213839181.

It can be written as a sum of positive squares in only one way, i.e., 169364196 + 12574116 = 13014^2 + 3546^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (181938313) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 139737 + ... + 141032.

Almost surely, 2^181938312 is an apocalyptic number.

181938312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

181938312 is an abundant number, since it is smaller than the sum of its proper divisors (327659238).

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

181938312 is a wasteful number, since it uses less digits than its factorization.

181938312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280787 (or 280774 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 181938312 is about 13488.4510600736. The cubic root of 181938312 is about 566.6410762761.

The spelling of 181938312 in words is "one hundred eighty-one million, nine hundred thirty-eight thousand, three hundred twelve".