644012 has 12 divisors (see below), whose sum is σ = 1133496. Its totient is φ = 320160.

The previous prime is 644009. The next prime is 644029. The reversal of 644012 is 210446.

It is a super-2 number, since 2×644012² = 829502912288, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 644012.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 587 + ... + 1277.

It is an arithmetic number, because the mean of its divisors is an integer number (94458).

2⁶⁴⁴⁰¹² is an apocalyptic number.

It is an amenable number.

644012 is a deficient number, since it is larger than the sum of its proper divisors (489484).

644012 is a wasteful number, since it uses less digits than its factorization.

644012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 928 (or 926 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 644012 is about 802.5035825465. The cubic root of 644012 is about 86.3570874577.

Adding to 644012 its reverse (210446), we get a palindrome (854458).

The spelling of 644012 in words is "six hundred forty-four thousand, twelve".