664431253 has 4 divisors (see below), whose sum is σ = 664564300. Its totient is φ = 664298208.

The previous prime is 664431223. The next prime is 664431289. The reversal of 664431253 is 352134466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 352134466 = 2 ⋅176067233.

It can be written as a sum of positive squares in 2 ways, for example, as 528172324 + 136258929 = 22982^2 + 11673^2 .

It is a cyclic number.

It is not a de Polignac number, because 664431253 - 2⁵ = 664431221 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 (664431203) 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, 58728 + ... + 69121.

It is an arithmetic number, because the mean of its divisors is an integer number (166141075).

Almost surely, 2^664431253 is an apocalyptic number.

It is an amenable number.

664431253 is a deficient number, since it is larger than the sum of its proper divisors (133047).

664431253 is a wasteful number, since it uses less digits than its factorization.

664431253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133046.

The product of its digits is 51840, while the sum is 34.

The square root of 664431253 is about 25776.5640262623. The cubic root of 664431253 is about 872.6029645072.

The spelling of 664431253 in words is "six hundred sixty-four million, four hundred thirty-one thousand, two hundred fifty-three".