644654461 has 8 divisors (see below), whose sum is σ = 706204800. Its totient is φ = 583595040.

The previous prime is 644654453. The next prime is 644654489. The reversal of 644654461 is 164456446.

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

It is a cyclic number.

It is not a de Polignac number, because 644654461 - 2³ = 644654453 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 (644654411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119976 + ... + 125233.

It is an arithmetic number, because the mean of its divisors is an integer number (88275600).

Almost surely, 2^644654461 is an apocalyptic number.

It is an amenable number.

644654461 is a deficient number, since it is larger than the sum of its proper divisors (61550339).

644654461 is a wasteful number, since it uses less digits than its factorization.

644654461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245459.

The product of its digits is 276480, while the sum is 40.

The square root of 644654461 is about 25390.0464946404. The cubic root of 644654461 is about 863.8579428404.

The spelling of 644654461 in words is "six hundred forty-four million, six hundred fifty-four thousand, four hundred sixty-one".