644041402 has 8 divisors (see below), whose sum is σ = 969911712. Its totient is φ = 320737500.

The previous prime is 644041397. The next prime is 644041403. The reversal of 644041402 is 204140446.

644041402 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (644041403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 640974 + ... + 641977.

It is an arithmetic number, because the mean of its divisors is an integer number (121238964).

Almost surely, 2^644041402 is an apocalyptic number.

644041402 is a deficient number, since it is larger than the sum of its proper divisors (325870310).

644041402 is a wasteful number, since it uses less digits than its factorization.

644041402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1283204.

The product of its (nonzero) digits is 3072, while the sum is 25.

The square root of 644041402 is about 25377.9708014648. The cubic root of 644041402 is about 863.5840163225.

Adding to 644041402 its reverse (204140446), we get a palindrome (848181848).

The spelling of 644041402 in words is "six hundred forty-four million, forty-one thousand, four hundred two".