661468180 has 12 divisors (see below), whose sum is σ = 1389083220. Its totient is φ = 264587264.

The previous prime is 661468169. The next prime is 661468189. The reversal of 661468180 is 81864166.

It can be written as a sum of positive squares in 2 ways, for example, as 487703056 + 173765124 = 22084^2 + 13182^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661468189) 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, 16536685 + ... + 16536724.

It is an arithmetic number, because the mean of its divisors is an integer number (115756935).

Almost surely, 2^661468180 is an apocalyptic number.

It is an amenable number.

661468180 is an abundant number, since it is smaller than the sum of its proper divisors (727615040).

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

661468180 is a wasteful number, since it uses less digits than its factorization.

661468180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33073418 (or 33073416 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 661468180 is about 25719.0236984221. The cubic root of 661468180 is about 871.3038888686.

The spelling of 661468180 in words is "six hundred sixty-one million, four hundred sixty-eight thousand, one hundred eighty".