661872424 has 48 divisors (see below), whose sum is σ = 1346575680. Its totient is φ = 304792320.

The previous prime is 661872401. The next prime is 661872433. The reversal of 661872424 is 424278166.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 105619 + ... + 111709.

It is an arithmetic number, because the mean of its divisors is an integer number (28053660).

Almost surely, 2^661872424 is an apocalyptic number.

It is an amenable number.

661872424 is an abundant number, since it is smaller than the sum of its proper divisors (684703256).

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

661872424 is a wasteful number, since it uses less digits than its factorization.

661872424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6178 (or 6157 counting only the distinct ones).

The product of its digits is 129024, while the sum is 40.

The square root of 661872424 is about 25726.8813500587. The cubic root of 661872424 is about 871.4813464564.

The spelling of 661872424 in words is "six hundred sixty-one million, eight hundred seventy-two thousand, four hundred twenty-four".