644462 has 16 divisors (see below), whose sum is σ = 1190112. Its totient is φ = 254880.

The previous prime is 644447. The next prime is 644489. The reversal of 644462 is 264446.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1589 + ... + 1952.

It is an arithmetic number, because the mean of its divisors is an integer number (74382).

2⁶⁴⁴⁴⁶² is an apocalyptic number.

644462 is a deficient number, since it is larger than the sum of its proper divisors (545650).

644462 is a wasteful number, since it uses less digits than its factorization.

644462 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3563.

The product of its digits is 4608, while the sum is 26.

The square root of 644462 is about 802.7839061665. The cubic root of 644462 is about 86.3771966284.

The spelling of 644462 in words is "six hundred forty-four thousand, four hundred sixty-two".