644351112 has 40 divisors (see below), whose sum is σ = 1804781550. Its totient is φ = 214783488.

The previous prime is 644351101. The next prime is 644351117. The reversal of 644351112 is 211153446.

It is a happy number.

644351112 is a `hidden beast` number, since 644 + 3 + 5 + 1 + 1 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 408605796 + 235745316 = 20214^2 + 15354^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (644351117) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 496537 + ... + 497832.

Almost surely, 2^644351112 is an apocalyptic number.

It is an amenable number.

644351112 is an abundant number, since it is smaller than the sum of its proper divisors (1160430438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644351112 is a wasteful number, since it uses less digits than its factorization.

644351112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994387 (or 994374 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 644351112 is about 25384.0720137649. The cubic root of 644351112 is about 863.7224224062.

The spelling of 644351112 in words is "six hundred forty-four million, three hundred fifty-one thousand, one hundred twelve".