666636432 has 240 divisors, whose sum is σ = 2279854080. Its totient is φ = 163848960.

The previous prime is 666636403. The next prime is 666636449. The reversal of 666636432 is 234636666.

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 772033 + ... + 772895.

It is an arithmetic number, because the mean of its divisors is an integer number (9499392).

Almost surely, 2^666636432 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 666636432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1139927040).

666636432 is an abundant number, since it is smaller than the sum of its proper divisors (1613217648).

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

666636432 is a wasteful number, since it uses less digits than its factorization.

666636432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 922 (or 905 counting only the distinct ones).

The product of its digits is 559872, while the sum is 42.

The square root of 666636432 is about 25819.3034762753. The cubic root of 666636432 is about 873.5672583296.

The spelling of 666636432 in words is "six hundred sixty-six million, six hundred thirty-six thousand, four hundred thirty-two".