644296441 has 4 divisors (see below), whose sum is σ = 678206800. Its totient is φ = 610386084.

The previous prime is 644296417. The next prime is 644296459. The reversal of 644296441 is 144692446.

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, and also an emirpimes, since its reverse is a distinct semiprime: 144692446 = 2 ⋅72346223.

It is a cyclic number.

It is not a de Polignac number, because 644296441 - 2⁵ = 644296409 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644296394 and 644296403.

It is not an unprimeable number, because it can be changed into a prime (644291441) 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, 16955151 + ... + 16955188.

It is an arithmetic number, because the mean of its divisors is an integer number (169551700).

Almost surely, 2^644296441 is an apocalyptic number.

It is an amenable number.

644296441 is a deficient number, since it is larger than the sum of its proper divisors (33910359).

644296441 is a wasteful number, since it uses less digits than its factorization.

644296441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33910358.

The product of its digits is 165888, while the sum is 40.

The square root of 644296441 is about 25382.9951148402. The cubic root of 644296441 is about 863.6979937454.

The spelling of 644296441 in words is "six hundred forty-four million, two hundred ninety-six thousand, four hundred forty-one".