644847485 has 16 divisors (see below), whose sum is σ = 821057472. Its totient is φ = 484512000.

The previous prime is 644847457. The next prime is 644847487. The reversal of 644847485 is 584748446.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-644847485 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644847487) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34010 + ... + 49460.

It is an arithmetic number, because the mean of its divisors is an integer number (51316092).

Almost surely, 2^644847485 is an apocalyptic number.

It is an amenable number.

644847485 is a deficient number, since it is larger than the sum of its proper divisors (176209987).

644847485 is a wasteful number, since it uses less digits than its factorization.

644847485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15964.

The product of its digits is 3440640, while the sum is 50.

The square root of 644847485 is about 25393.8473847505. The cubic root of 644847485 is about 863.9441537156.

The spelling of 644847485 in words is "six hundred forty-four million, eight hundred forty-seven thousand, four hundred eighty-five".