661574672 has 20 divisors (see below), whose sum is σ = 1398328656. Its totient is φ = 300715680.

The previous prime is 661574671. The next prime is 661574743. The reversal of 661574672 is 276475166.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (661574671) 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, 1879298 + ... + 1879649.

Almost surely, 2^661574672 is an apocalyptic number.

It is an amenable number.

661574672 is an abundant number, since it is smaller than the sum of its proper divisors (736753984).

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

661574672 is a wasteful number, since it uses less digits than its factorization.

661574672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3758966 (or 3758960 counting only the distinct ones).

The product of its digits is 423360, while the sum is 44.

The square root of 661574672 is about 25721.0939114183. The cubic root of 661574672 is about 871.3506444131.

The spelling of 661574672 in words is "six hundred sixty-one million, five hundred seventy-four thousand, six hundred seventy-two".