666257247 has 6 divisors (see below), whose sum is σ = 962371592. Its totient is φ = 444171492.

The previous prime is 666257243. The next prime is 666257299. The reversal of 666257247 is 742752666.

It is not a de Polignac number, because 666257247 - 2² = 666257243 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 (666257243) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 37014283 + ... + 37014300.

Almost surely, 2^666257247 is an apocalyptic number.

666257247 is a deficient number, since it is larger than the sum of its proper divisors (296114345).

666257247 is a wasteful number, since it uses less digits than its factorization.

666257247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74028589 (or 74028586 counting only the distinct ones).

The product of its digits is 846720, while the sum is 45.

The square root of 666257247 is about 25811.9593793265. The cubic root of 666257247 is about 873.4015976041.

The spelling of 666257247 in words is "six hundred sixty-six million, two hundred fifty-seven thousand, two hundred forty-seven".