644355097 has 16 divisors (see below), whose sum is σ = 713180160. Its totient is φ = 579059712.

The previous prime is 644355083. The next prime is 644355133. The reversal of 644355097 is 790553446.

It is not a de Polignac number, because 644355097 - 2⁷ = 644354969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644355077) 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 15 ways as a sum of consecutive naturals, for example, 299608 + ... + 301750.

It is an arithmetic number, because the mean of its divisors is an integer number (44573760).

Almost surely, 2^644355097 is an apocalyptic number.

It is an amenable number.

644355097 is a deficient number, since it is larger than the sum of its proper divisors (68825063).

644355097 is a wasteful number, since it uses less digits than its factorization.

644355097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2952.

The product of its (nonzero) digits is 453600, while the sum is 43.

The square root of 644355097 is about 25384.1505077479. The cubic root of 644355097 is about 863.7242029710.

The spelling of 644355097 in words is "six hundred forty-four million, three hundred fifty-five thousand, ninety-seven".