644266089 has 16 divisors (see below), whose sum is σ = 980266240. Its totient is φ = 417901680.

The previous prime is 644266069. The next prime is 644266151. The reversal of 644266089 is 980662446.

644266089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644266089 - 2⁵ = 644266057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644266019) 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, 321457 + ... + 323454.

It is an arithmetic number, because the mean of its divisors is an integer number (61266640).

Almost surely, 2^644266089 is an apocalyptic number.

It is an amenable number.

644266089 is a deficient number, since it is larger than the sum of its proper divisors (336000151).

644266089 is a wasteful number, since it uses less digits than its factorization.

644266089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644957 (or 644951 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 644266089 is about 25382.3972272124. The cubic root of 644266089 is about 863.6844309548.

The spelling of 644266089 in words is "six hundred forty-four million, two hundred sixty-six thousand, eighty-nine".