666435631 has 8 divisors (see below), whose sum is σ = 693986400. Its totient is φ = 639189600.

The previous prime is 666435611. The next prime is 666435661. The reversal of 666435631 is 136534666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666435631 - 2²³ = 658047023 is a prime.

It is a super-2 number, since 2×666435631² = 888272900532736322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666435611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71716 + ... + 80473.

It is an arithmetic number, because the mean of its divisors is an integer number (86748300).

Almost surely, 2^666435631 is an apocalyptic number.

666435631 is a deficient number, since it is larger than the sum of its proper divisors (27550769).

666435631 is a wasteful number, since it uses less digits than its factorization.

666435631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152369.

The product of its digits is 233280, while the sum is 40.

The square root of 666435631 is about 25815.4146005831. The cubic root of 666435631 is about 873.4795389541.

The spelling of 666435631 in words is "six hundred sixty-six million, four hundred thirty-five thousand, six hundred thirty-one".