168139188 has 54 divisors (see below), whose sum is σ = 494414466. Its totient is φ = 48039264.

The previous prime is 168139183. The next prime is 168139217. The reversal of 168139188 is 881931861.

It can be written as a sum of positive squares in only one way, i.e., 165173904 + 2965284 = 12852^2 + 1722^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168139183) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 45895 + ... + 49422.

Almost surely, 2^168139188 is an apocalyptic number.

168139188 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

168139188 is an abundant number, since it is smaller than the sum of its proper divisors (326275278).

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

168139188 is a wasteful number, since it uses less digits than its factorization.

168139188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95341 (or 95329 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The square root of 168139188 is about 12966.8495788299. The cubic root of 168139188 is about 551.9371777907.

The spelling of 168139188 in words is "one hundred sixty-eight million, one hundred thirty-nine thousand, one hundred eighty-eight".