664422643 has 4 divisors (see below), whose sum is σ = 693310608. Its totient is φ = 635534680.

The previous prime is 664422631. The next prime is 664422697. The reversal of 664422643 is 346224466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 664422643 - 2²⁵ = 630868211 is a prime.

It is a super-2 number, since 2×664422643² = 882914897062210898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664422613) 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, 14443948 + ... + 14443993.

It is an arithmetic number, because the mean of its divisors is an integer number (173327652).

Almost surely, 2^664422643 is an apocalyptic number.

664422643 is a deficient number, since it is larger than the sum of its proper divisors (28887965).

664422643 is a wasteful number, since it uses less digits than its factorization.

664422643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28887964.

The product of its digits is 165888, while the sum is 37.

The square root of 664422643 is about 25776.3970135471. The cubic root of 664422643 is about 872.5991952966.

The spelling of 664422643 in words is "six hundred sixty-four million, four hundred twenty-two thousand, six hundred forty-three".