666645432 has 64 divisors (see below), whose sum is σ = 1742376960. Its totient is φ = 212150400.

The previous prime is 666645431. The next prime is 666645443. The reversal of 666645432 is 234546666.

It is a super-2 number, since 2×666645432² = 888832264012933248, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666645431) by changing a digit.

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, 452457 + ... + 453927.

It is an arithmetic number, because the mean of its divisors is an integer number (27224640).

Almost surely, 2^666645432 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 666645432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (871188480).

666645432 is an abundant number, since it is smaller than the sum of its proper divisors (1075731528).

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

666645432 is a wasteful number, since it uses less digits than its factorization.

666645432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2324 (or 2320 counting only the distinct ones).

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

The square root of 666645432 is about 25819.4777638898. The cubic root of 666645432 is about 873.5711895428.

The spelling of 666645432 in words is "six hundred sixty-six million, six hundred forty-five thousand, four hundred thirty-two".