644052 has 24 divisors (see below), whose sum is σ = 1516032. Its totient is φ = 212800.

The previous prime is 644051. The next prime is 644053. The reversal of 644052 is 250446.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (644051) and next prime (644053).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644051) 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 7 ways as a sum of consecutive naturals, for example, 2152 + ... + 2432.

It is an arithmetic number, because the mean of its divisors is an integer number (63168).

2⁶⁴⁴⁰⁵² is an apocalyptic number.

It is an amenable number.

644052 is an abundant number, since it is smaller than the sum of its proper divisors (871980).

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

644052 is a wasteful number, since it uses less digits than its factorization.

644052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 644052 is about 802.5285041667. The cubic root of 644052 is about 86.3588753188.

Adding to 644052 its reverse (250446), we get a palindrome (894498).

The spelling of 644052 in words is "six hundred forty-four thousand, fifty-two".