666384657 has 8 divisors (see below), whose sum is σ = 889491840. Its totient is φ = 443766960.

The previous prime is 666384647. The next prime is 666384703. The reversal of 666384657 is 756483666.

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

It is not a de Polignac number, because 666384657 - 2¹⁰ = 666383633 is a prime.

It is a super-2 number, since 2×666384657² = 888137022170015298, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666384637) 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, 119182 + ... + 124647.

It is an arithmetic number, because the mean of its divisors is an integer number (111186480).

Almost surely, 2^666384657 is an apocalyptic number.

It is an amenable number.

666384657 is a deficient number, since it is larger than the sum of its proper divisors (223107183).

666384657 is a wasteful number, since it uses less digits than its factorization.

666384657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244743.

The product of its digits is 4354560, while the sum is 51.

The square root of 666384657 is about 25814.4273033511. The cubic root of 666384657 is about 873.4572682955.

Subtracting 666384657 from its reverse (756483666), we obtain a palindrome (90099009).

The spelling of 666384657 in words is "six hundred sixty-six million, three hundred eighty-four thousand, six hundred fifty-seven".