661475660 has 24 divisors (see below), whose sum is σ = 1395174480. Its totient is φ = 263433024.

The previous prime is 661475641. The next prime is 661475663. The reversal of 661475660 is 66574166.

661475660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (661475663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67634 + ... + 76793.

It is an arithmetic number, because the mean of its divisors is an integer number (58132270).

Almost surely, 2^661475660 is an apocalyptic number.

It is an amenable number.

661475660 is an abundant number, since it is smaller than the sum of its proper divisors (733698820).

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

661475660 is a wasteful number, since it uses less digits than its factorization.

661475660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144665 (or 144663 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 41.

The square root of 661475660 is about 25719.1691156616. The cubic root of 661475660 is about 871.3071731427.

The spelling of 661475660 in words is "six hundred sixty-one million, four hundred seventy-five thousand, six hundred sixty".