644362 has 8 divisors (see below), whose sum is σ = 972000. Its totient is φ = 320364.

The previous prime is 644359. The next prime is 644363. The reversal of 644362 is 263446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (644363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 412 + ... + 1207.

It is an arithmetic number, because the mean of its divisors is an integer number (121500).

2⁶⁴⁴³⁶² is an apocalyptic number.

644362 is a deficient number, since it is larger than the sum of its proper divisors (327638).

644362 is a wasteful number, since it uses less digits than its factorization.

644362 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1820.

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

The square root of 644362 is about 802.7216204887. The cubic root of 644362 is about 86.3727287330.

The spelling of 644362 in words is "six hundred forty-four thousand, three hundred sixty-two".