666709632 has 48 divisors (see below), whose sum is σ = 1918529730. Its totient is φ = 222236160.

The previous prime is 666709619. The next prime is 666709663. The reversal of 666709632 is 236907666.

666709632 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 465523776 + 201185856 = 21576^2 + 14184^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 288219 + ... + 290522.

Almost surely, 2^666709632 is an apocalyptic number.

It is an amenable number.

666709632 is an abundant number, since it is smaller than the sum of its proper divisors (1251820098).

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

666709632 is a wasteful number, since it uses less digits than its factorization.

666709632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578761 (or 578746 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 45.

The square root of 666709632 is about 25820.7209814134. The cubic root of 666709632 is about 873.5992311711.

The spelling of 666709632 in words is "six hundred sixty-six million, seven hundred nine thousand, six hundred thirty-two".