644315461 has 8 divisors (see below), whose sum is σ = 653635584. Its totient is φ = 635053200.

The previous prime is 644315443. The next prime is 644315467. The reversal of 644315461 is 164513446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644315461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644315467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8220 + ... + 36826.

It is an arithmetic number, because the mean of its divisors is an integer number (81704448).

Almost surely, 2^644315461 is an apocalyptic number.

It is an amenable number.

644315461 is a deficient number, since it is larger than the sum of its proper divisors (9320123).

644315461 is a wasteful number, since it uses less digits than its factorization.

644315461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28931.

The product of its digits is 34560, while the sum is 34.

The square root of 644315461 is about 25383.3697723529. The cubic root of 644315461 is about 863.7064926150.

It can be divided in two parts, 6443 and 15461, that added together give a square (21904 = 148²).

The spelling of 644315461 in words is "six hundred forty-four million, three hundred fifteen thousand, four hundred sixty-one".