644294445 has 16 divisors (see below), whose sum is σ = 1046258880. Its totient is φ = 338494464.

The previous prime is 644294437. The next prime is 644294513. The reversal of 644294445 is 544492446.

It is a happy number.

It is not a de Polignac number, because 644294445 - 2³ = 644294437 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644294397 and 644294406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 319540 + ... + 321549.

It is an arithmetic number, because the mean of its divisors is an integer number (65391180).

Almost surely, 2^644294445 is an apocalyptic number.

It is an amenable number.

644294445 is a deficient number, since it is larger than the sum of its proper divisors (401964435).

644294445 is a wasteful number, since it uses less digits than its factorization.

644294445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641164.

The product of its digits is 552960, while the sum is 42.

The square root of 644294445 is about 25382.9557971486. The cubic root of 644294445 is about 863.6971018460.

The spelling of 644294445 in words is "six hundred forty-four million, two hundred ninety-four thousand, four hundred forty-five".