644301407 has 4 divisors (see below), whose sum is σ = 644769336. Its totient is φ = 643833480.

The previous prime is 644301401. The next prime is 644301421. The reversal of 644301407 is 704103446.

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 644301407 - 2⁴ = 644301391 is a prime.

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 644301407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644301401) 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, 231893 + ... + 234654.

It is an arithmetic number, because the mean of its divisors is an integer number (161192334).

Almost surely, 2^644301407 is an apocalyptic number.

644301407 is a deficient number, since it is larger than the sum of its proper divisors (467929).

644301407 is a wasteful number, since it uses less digits than its factorization.

644301407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467928.

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 644301407 is about 25383.0929360470. The cubic root of 644301407 is about 863.7002127619.

The spelling of 644301407 in words is "six hundred forty-four million, three hundred one thousand, four hundred seven".