644122 has 8 divisors (see below), whose sum is σ = 969696. Its totient is φ = 320892.

The previous prime is 644117. The next prime is 644123. The reversal of 644122 is 221446.

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

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 644122.

It is not an unprimeable number, because it can be changed into a prime (644123) 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, 523 + ... + 1249.

It is an arithmetic number, because the mean of its divisors is an integer number (121212).

2⁶⁴⁴¹²² is an apocalyptic number.

644122 is a deficient number, since it is larger than the sum of its proper divisors (325574).

644122 is a wasteful number, since it uses less digits than its factorization.

644122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1172.

The product of its digits is 384, while the sum is 19.

The square root of 644122 is about 802.5721151398. The cubic root of 644122 is about 86.3620038976.

Adding to 644122 its reverse (221446), we get a palindrome (865568).

It can be divided in two parts, 64 and 4122, that added together give a triangular number (4186 = T₉₁).

The spelling of 644122 in words is "six hundred forty-four thousand, one hundred twenty-two".