666647724 has 48 divisors (see below), whose sum is σ = 1663054848. Its totient is φ = 207107328.

The previous prime is 666647713. The next prime is 666647743. The reversal of 666647724 is 427746666.

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 15 ways as a sum of consecutive naturals, for example, 5149 + ... + 36875.

It is an arithmetic number, because the mean of its divisors is an integer number (34646976).

Almost surely, 2^666647724 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666647724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (831527424).

666647724 is an abundant number, since it is smaller than the sum of its proper divisors (996407124).

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

666647724 is a wasteful number, since it uses less digits than its factorization.

666647724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31854 (or 31852 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 48.

The square root of 666647724 is about 25819.5221489477. The cubic root of 666647724 is about 873.5721906862.

The spelling of 666647724 in words is "six hundred sixty-six million, six hundred forty-seven thousand, seven hundred twenty-four".