644562 has 12 divisors (see below), whose sum is σ = 1396590. Its totient is φ = 214848.

The previous prime is 644557. The next prime is 644563. The reversal of 644562 is 265446.

It is a happy number.

644562 is nontrivially palindromic in base 15.

It can be written as a sum of positive squares in only one way, i.e., 549081 + 95481 = 741^2 + 309^2 .

It is not an unprimeable number, because it can be changed into a prime (644563) 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 5 ways as a sum of consecutive naturals, for example, 17887 + ... + 17922.

2⁶⁴⁴⁵⁶² is an apocalyptic number.

644562 is an abundant number, since it is smaller than the sum of its proper divisors (752028).

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

644562 is a wasteful number, since it uses less digits than its factorization.

644562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35817 (or 35814 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 644562 is about 802.8461870122. The cubic root of 644562 is about 86.3816640617.

The spelling of 644562 in words is "six hundred forty-four thousand, five hundred sixty-two".