644937 has 8 divisors (see below), whose sum is σ = 865440. Its totient is φ = 427200.

The previous prime is 644933. The next prime is 644951. The reversal of 644937 is 739446.

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

It is not a de Polignac number, because 644937 - 2² = 644933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644898 and 644907.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 644937.

It is not an unprimeable number, because it can be changed into a prime (644933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64 + ... + 1137.

It is an arithmetic number, because the mean of its divisors is an integer number (108180).

2⁶⁴⁴⁹³⁷ is an apocalyptic number.

It is an amenable number.

644937 is a deficient number, since it is larger than the sum of its proper divisors (220503).

644937 is a wasteful number, since it uses less digits than its factorization.

644937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1383.

The product of its digits is 18144, while the sum is 33.

The square root of 644937 is about 803.0796971659. The cubic root of 644937 is about 86.3984128224.

The spelling of 644937 in words is "six hundred forty-four thousand, nine hundred thirty-seven".