181338660 has 144 divisors (see below), whose sum is σ = 613267200. Its totient is φ = 43103232.

The previous prime is 181338631. The next prime is 181338667. The reversal of 181338660 is 66833181.

It is a super-2 number, since 2×181338660² = 65767419221191200, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (181338667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 56581 + ... + 59699.

It is an arithmetic number, because the mean of its divisors is an integer number (4258800).

Almost surely, 2^181338660 is an apocalyptic number.

181338660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181338660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306633600).

181338660 is an abundant number, since it is smaller than the sum of its proper divisors (431928540).

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

181338660 is a wasteful number, since it uses less digits than its factorization.

181338660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3170 (or 3165 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 181338660 is about 13466.2043650020. The cubic root of 181338660 is about 566.0178587347.

The spelling of 181338660 in words is "one hundred eighty-one million, three hundred thirty-eight thousand, six hundred sixty".