181339728 has 80 divisors (see below), whose sum is σ = 494968320. Its totient is φ = 57092992.

The previous prime is 181339693. The next prime is 181339733. The reversal of 181339728 is 827933181.

It is a super-2 number, since 2×181339728² = 65768193902227968, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 181339728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90643 + ... + 92621.

It is an arithmetic number, because the mean of its divisors is an integer number (6187104).

Almost surely, 2^181339728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181339728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247484160).

181339728 is an abundant number, since it is smaller than the sum of its proper divisors (313628592).

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

181339728 is a wasteful number, since it uses less digits than its factorization.

181339728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2096 (or 2090 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 181339728 is about 13466.2440197703. The cubic root of 181339728 is about 566.0189699261.

The spelling of 181339728 in words is "one hundred eighty-one million, three hundred thirty-nine thousand, seven hundred twenty-eight".