644236 has 6 divisors (see below), whose sum is σ = 1127420. Its totient is φ = 322116.

The previous prime is 644227. The next prime is 644239. The reversal of 644236 is 632446.

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 644236.

It is not an unprimeable number, because it can be changed into a prime (644239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80526 + ... + 80533.

2⁶⁴⁴²³⁶ is an apocalyptic number.

It is an amenable number.

644236 is a deficient number, since it is larger than the sum of its proper divisors (483184).

644236 is a wasteful number, since it uses less digits than its factorization.

644236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161063 (or 161061 counting only the distinct ones).

The product of its digits is 3456, while the sum is 25.

The square root of 644236 is about 802.6431336528. The cubic root of 644236 is about 86.3670985265.

The spelling of 644236 in words is "six hundred forty-four thousand, two hundred thirty-six".