644450577 has 4 divisors (see below), whose sum is σ = 859267440. Its totient is φ = 429633716.

The previous prime is 644450551. The next prime is 644450579. The reversal of 644450577 is 775054446.

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 644450577 - 2⁷ = 644450449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644450579) 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, 107408427 + ... + 107408432.

It is an arithmetic number, because the mean of its divisors is an integer number (214816860).

Almost surely, 2^644450577 is an apocalyptic number.

It is an amenable number.

644450577 is a deficient number, since it is larger than the sum of its proper divisors (214816863).

644450577 is a wasteful number, since it uses less digits than its factorization.

644450577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214816862.

The product of its (nonzero) digits is 470400, while the sum is 42.

The square root of 644450577 is about 25386.0311391915. The cubic root of 644450577 is about 863.7668628409.

The spelling of 644450577 in words is "six hundred forty-four million, four hundred fifty thousand, five hundred seventy-seven".