644835797 has 8 divisors (see below), whose sum is σ = 675043200. Its totient is φ = 614809360.

The previous prime is 644835787. The next prime is 644835799. The reversal of 644835797 is 797538446.

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

It is a cyclic number.

It is not a de Polignac number, because 644835797 - 2¹² = 644831701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644835799) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37922 + ... + 52227.

It is an arithmetic number, because the mean of its divisors is an integer number (84380400).

Almost surely, 2^644835797 is an apocalyptic number.

It is an amenable number.

644835797 is a deficient number, since it is larger than the sum of its proper divisors (30207403).

644835797 is a wasteful number, since it uses less digits than its factorization.

644835797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90483.

The product of its digits is 5080320, while the sum is 53.

The square root of 644835797 is about 25393.6172492223. The cubic root of 644835797 is about 863.9389339592.

The spelling of 644835797 in words is "six hundred forty-four million, eight hundred thirty-five thousand, seven hundred ninety-seven".