666635424 has 192 divisors, whose sum is σ = 2173360896. Its totient is φ = 174219264.

The previous prime is 666635419. The next prime is 666635449. The reversal of 666635424 is 424536666.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1196554 + ... + 1197110.

It is an arithmetic number, because the mean of its divisors is an integer number (11319588).

Almost surely, 2^666635424 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 666635424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1086680448).

666635424 is an abundant number, since it is smaller than the sum of its proper divisors (1506725472).

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

666635424 is a wasteful number, since it uses less digits than its factorization.

666635424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727 (or 719 counting only the distinct ones).

The product of its digits is 622080, while the sum is 42.

The square root of 666635424 is about 25819.2839559892. The cubic root of 666635424 is about 873.5668180315.

The spelling of 666635424 in words is "six hundred sixty-six million, six hundred thirty-five thousand, four hundred twenty-four".