666432397 has 4 divisors (see below), whose sum is σ = 666550300. Its totient is φ = 666314496.

The previous prime is 666432379. The next prime is 666432433. The reversal of 666432397 is 793234666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3575881 + 662856516 = 1891^2 + 25746^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666432397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666430397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50022 + ... + 61927.

It is an arithmetic number, because the mean of its divisors is an integer number (166637575).

Almost surely, 2^666432397 is an apocalyptic number.

It is an amenable number.

666432397 is a deficient number, since it is larger than the sum of its proper divisors (117903).

666432397 is a wasteful number, since it uses less digits than its factorization.

666432397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117902.

The product of its digits is 979776, while the sum is 46.

The square root of 666432397 is about 25815.3519635119. The cubic root of 666432397 is about 873.4781260458.

The spelling of 666432397 in words is "six hundred sixty-six million, four hundred thirty-two thousand, three hundred ninety-seven".