644481442 has 32 divisors (see below), whose sum is σ = 1107328320. Its totient is φ = 278604480.

The previous prime is 644481427. The next prime is 644481443. The reversal of 644481442 is 244184446.

It is not an unprimeable number, because it can be changed into a prime (644481443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35208 + ... + 50284.

It is an arithmetic number, because the mean of its divisors is an integer number (34604010).

Almost surely, 2^644481442 is an apocalyptic number.

644481442 is a deficient number, since it is larger than the sum of its proper divisors (462846878).

644481442 is a wasteful number, since it uses less digits than its factorization.

644481442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15186.

The product of its digits is 98304, while the sum is 37.

The square root of 644481442 is about 25386.6390449780. The cubic root of 644481442 is about 863.7806522297.

The spelling of 644481442 in words is "six hundred forty-four million, four hundred eighty-one thousand, four hundred forty-two".