644450297 has 8 divisors (see below), whose sum is σ = 688985856. Its totient is φ = 600651072.

The previous prime is 644450293. The next prime is 644450309. The reversal of 644450297 is 792054446.

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

It is not a de Polignac number, because 644450297 - 2² = 644450293 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644450293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182273 + ... + 185774.

It is an arithmetic number, because the mean of its divisors is an integer number (86123232).

Almost surely, 2^644450297 is an apocalyptic number.

It is an amenable number.

644450297 is a deficient number, since it is larger than the sum of its proper divisors (44535559).

644450297 is a wasteful number, since it uses less digits than its factorization.

644450297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368167.

The product of its (nonzero) digits is 241920, while the sum is 41.

The square root of 644450297 is about 25386.0256243470. The cubic root of 644450297 is about 863.7667377448.

The spelling of 644450297 in words is "six hundred forty-four million, four hundred fifty thousand, two hundred ninety-seven".