664312501 has 4 divisors (see below), whose sum is σ = 672721600. Its totient is φ = 655903404.

The previous prime is 664312499. The next prime is 664312507. The reversal of 664312501 is 105213466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 664312501 - 2¹ = 664312499 is a prime.

It is a super-2 number, since 2×664312501² = 882622197969750002, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664312501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664312507) 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, 4204431 + ... + 4204588.

It is an arithmetic number, because the mean of its divisors is an integer number (168180400).

Almost surely, 2^664312501 is an apocalyptic number.

It is an amenable number.

664312501 is a deficient number, since it is larger than the sum of its proper divisors (8409099).

664312501 is an equidigital number, since it uses as much as digits as its factorization.

664312501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8409098.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 664312501 is about 25774.2604355586. The cubic root of 664312501 is about 872.5509754209.

Adding to 664312501 its reverse (105213466), we get a palindrome (769525967).

The spelling of 664312501 in words is "six hundred sixty-four million, three hundred twelve thousand, five hundred one".