181336640 has 28 divisors (see below), whose sum is σ = 431808636. Its totient is φ = 72534528.

The previous prime is 181336583. The next prime is 181336643. The reversal of 181336640 is 46633181.

181336640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 100480576 + 80856064 = 10024^2 + 8992^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 181336597 and 181336606.

It is not an unprimeable number, because it can be changed into a prime (181336643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283019 + ... + 283658.

It is an arithmetic number, because the mean of its divisors is an integer number (15421737).

Almost surely, 2^181336640 is an apocalyptic number.

181336640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181336640 is an abundant number, since it is smaller than the sum of its proper divisors (250471996).

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

181336640 is an equidigital number, since it uses as much as digits as its factorization.

181336640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566694 (or 566684 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 181336640 is about 13466.1293622184. The cubic root of 181336640 is about 566.0157570311.

The spelling of 181336640 in words is "one hundred eighty-one million, three hundred thirty-six thousand, six hundred forty".