664405629 has 4 divisors (see below), whose sum is σ = 885874176. Its totient is φ = 442937084.

The previous prime is 664405601. The next prime is 664405649. The reversal of 664405629 is 926504466.

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 664405629 - 2¹⁷ = 664274557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664405649) 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, 110734269 + ... + 110734274.

It is an arithmetic number, because the mean of its divisors is an integer number (221468544).

Almost surely, 2^664405629 is an apocalyptic number.

It is an amenable number.

664405629 is a deficient number, since it is larger than the sum of its proper divisors (221468547).

664405629 is a wasteful number, since it uses less digits than its factorization.

664405629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221468546.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 664405629 is about 25776.0669808254. The cubic root of 664405629 is about 872.5917469605.

The spelling of 664405629 in words is "six hundred sixty-four million, four hundred five thousand, six hundred twenty-nine".