644918954 has 32 divisors (see below), whose sum is σ = 1009883136. Its totient is φ = 308629440.

The previous prime is 644918951. The next prime is 644918959. The reversal of 644918954 is 459819446.

644918954 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (644918951) 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, 1531664 + ... + 1532084.

It is an arithmetic number, because the mean of its divisors is an integer number (31558848).

Almost surely, 2^644918954 is an apocalyptic number.

644918954 is a deficient number, since it is larger than the sum of its proper divisors (364964182).

644918954 is a wasteful number, since it uses less digits than its factorization.

644918954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750.

The product of its digits is 1244160, while the sum is 50.

The square root of 644918954 is about 25395.2545567080. The cubic root of 644918954 is about 863.9760697604.

The spelling of 644918954 in words is "six hundred forty-four million, nine hundred eighteen thousand, nine hundred fifty-four".