644932 has 6 divisors (see below), whose sum is σ = 1128638. Its totient is φ = 322464.

The previous prime is 644923. The next prime is 644933. The reversal of 644932 is 239446.

644932 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 614656 + 30276 = 784^2 + 174^2 .

It is a d-powerful number, because it can be written as 6⁶ + 4⁵ + 9⁶ + 4⁸ + 3⁵ + 2⁵ .

It is a self number, because there is not a number n which added to its sum of digits gives 644932.

It is not an unprimeable number, because it can be changed into a prime (644933) by changing a digit.

644932 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80613 + ... + 80620.

2⁶⁴⁴⁹³² is an apocalyptic number.

It is an amenable number.

644932 is a deficient number, since it is larger than the sum of its proper divisors (483706).

644932 is a wasteful number, since it uses less digits than its factorization.

644932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161237 (or 161235 counting only the distinct ones).

The product of its digits is 5184, while the sum is 28.

The square root of 644932 is about 803.0765841438. The cubic root of 644932 is about 86.3981895483.

The spelling of 644932 in words is "six hundred forty-four thousand, nine hundred thirty-two".