661252672 has 28 divisors (see below), whose sum is σ = 1389362220. Its totient is φ = 311177216.

The previous prime is 661252663. The next prime is 661252703. The reversal of 661252672 is 276252166.

It can be written as a sum of positive squares in 2 ways, for example, as 535274496 + 125978176 = 23136^2 + 11224^2 .

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, 302797 + ... + 304972.

Almost surely, 2^661252672 is an apocalyptic number.

It is an amenable number.

661252672 is an abundant number, since it is smaller than the sum of its proper divisors (728109548).

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

661252672 is a wasteful number, since it uses less digits than its factorization.

661252672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607798 (or 607788 counting only the distinct ones).

The product of its digits is 60480, while the sum is 37.

The square root of 661252672 is about 25714.8336957485. The cubic root of 661252672 is about 871.2092542562.

The spelling of 661252672 in words is "six hundred sixty-one million, two hundred fifty-two thousand, six hundred seventy-two".