181831680 has 144 divisors (see below), whose sum is σ = 630515340. Its totient is φ = 48463872.

The previous prime is 181831651. The next prime is 181831697. The reversal of 181831680 is 86138181.

It can be written as a sum of positive squares in 2 ways, for example, as 172975104 + 8856576 = 13152^2 + 2976^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 91174 + ... + 93146.

Almost surely, 2^181831680 is an apocalyptic number.

181831680 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 181831680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315257670).

181831680 is an abundant number, since it is smaller than the sum of its proper divisors (448683660).

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

181831680 is a wasteful number, since it uses less digits than its factorization.

181831680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2006 (or 1983 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 181831680 is about 13484.4977659533. The cubic root of 181831680 is about 566.5303539867.

The spelling of 181831680 in words is "one hundred eighty-one million, eight hundred thirty-one thousand, six hundred eighty".