181008640 has 36 divisors (see below), whose sum is σ = 433575324. Its totient is φ = 72402944.

The previous prime is 181008617. The next prime is 181008677. The reversal of 181008640 is 46800181.

It can be written as a sum of positive squares in 2 ways, for example, as 108826624 + 72182016 = 10432^2 + 8496^2 .

It is a super-3 number, since 3×181008640³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 181008599 and 181008608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69427 + ... + 71986.

It is an arithmetic number, because the mean of its divisors is an integer number (12043759).

Almost surely, 2^181008640 is an apocalyptic number.

181008640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181008640 is an abundant number, since it is smaller than the sum of its proper divisors (252566684).

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

181008640 is an equidigital number, since it uses as much as digits as its factorization.

181008640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141434 (or 141420 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 181008640 is about 13453.9451463130. The cubic root of 181008640 is about 565.6742830800.

The spelling of 181008640 in words is "one hundred eighty-one million, eight thousand, six hundred forty".