666691532 has 24 divisors (see below), whose sum is σ = 1322588400. Its totient is φ = 291508416.

The previous prime is 666691523. The next prime is 666691579. The reversal of 666691532 is 235196666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336407 + ... + 338382.

It is an arithmetic number, because the mean of its divisors is an integer number (55107850).

Almost surely, 2^666691532 is an apocalyptic number.

It is an amenable number.

666691532 is a deficient number, since it is larger than the sum of its proper divisors (655896868).

666691532 is a wasteful number, since it uses less digits than its factorization.

666691532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674825 (or 674823 counting only the distinct ones).

The product of its digits is 349920, while the sum is 44.

The square root of 666691532 is about 25820.3704853358. The cubic root of 666691532 is about 873.5913255360.

The spelling of 666691532 in words is "six hundred sixty-six million, six hundred ninety-one thousand, five hundred thirty-two".