644461011 has 6 divisors (see below), whose sum is σ = 930888140. Its totient is φ = 429640668.

The previous prime is 644460977. The next prime is 644461031. The reversal of 644461011 is 110164446.

644461011 is a `hidden beast` number, since 6 + 4 + 44 + 610 + 1 + 1 = 666.

It is not a de Polignac number, because 644461011 - 2¹¹ = 644458963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644461031) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35803381 + ... + 35803398.

Almost surely, 2^644461011 is an apocalyptic number.

644461011 is a deficient number, since it is larger than the sum of its proper divisors (286427129).

644461011 is a wasteful number, since it uses less digits than its factorization.

644461011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71606785 (or 71606782 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 644461011 is about 25386.2366450799. The cubic root of 644461011 is about 863.7715244318.

The spelling of 644461011 in words is "six hundred forty-four million, four hundred sixty-one thousand, eleven".