644950 has 12 divisors (see below), whose sum is σ = 1199700. Its totient is φ = 257960.

The previous prime is 644933. The next prime is 644951. The reversal of 644950 is 59446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644951) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6400 + ... + 6499.

It is an arithmetic number, because the mean of its divisors is an integer number (99975).

2⁶⁴⁴⁹⁵⁰ is an apocalyptic number.

644950 is a deficient number, since it is larger than the sum of its proper divisors (554750).

644950 is a wasteful number, since it uses less digits than its factorization.

644950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12911 (or 12906 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 644950 is about 803.0877909668. The cubic root of 644950 is about 86.3989933296.

The spelling of 644950 in words is "six hundred forty-four thousand, nine hundred fifty".