661324818 has 32 divisors (see below), whose sum is σ = 1649018880. Its totient is φ = 171772560.

The previous prime is 661324813. The next prime is 661324841. The reversal of 661324818 is 818423166.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (661324813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 715258 + ... + 716181.

It is an arithmetic number, because the mean of its divisors is an integer number (51531840).

Almost surely, 2^661324818 is an apocalyptic number.

661324818 is an abundant number, since it is smaller than the sum of its proper divisors (987694062).

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

661324818 is a wasteful number, since it uses less digits than its factorization.

661324818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1431462.

The product of its digits is 55296, while the sum is 39.

The square root of 661324818 is about 25716.2364664816. The cubic root of 661324818 is about 871.2409375445.

The spelling of 661324818 in words is "six hundred sixty-one million, three hundred twenty-four thousand, eight hundred eighteen".