644457070 has 32 divisors (see below), whose sum is σ = 1181727936. Its totient is φ = 252979200.

The previous prime is 644457061. The next prime is 644457071. The reversal of 644457070 is 70754446.

644457070 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644457071) 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, 351055 + ... + 352885.

It is an arithmetic number, because the mean of its divisors is an integer number (36928998).

Almost surely, 2^644457070 is an apocalyptic number.

644457070 is a deficient number, since it is larger than the sum of its proper divisors (537270866).

644457070 is a wasteful number, since it uses less digits than its factorization.

644457070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2476.

The product of its (nonzero) digits is 94080, while the sum is 37.

The square root of 644457070 is about 25386.1590241612. The cubic root of 644457070 is about 863.7697637199.

The spelling of 644457070 in words is "six hundred forty-four million, four hundred fifty-seven thousand, seventy".