646397917 has 8 divisors (see below), whose sum is σ = 742275360. Its totient is φ = 556706160.

The previous prime is 646397903. The next prime is 646397929. The reversal of 646397917 is 719793646.

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 646397917 - 2⁷ = 646397789 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 (646392917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1546198 + ... + 1546615.

It is an arithmetic number, because the mean of its divisors is an integer number (92784420).

Almost surely, 2^646397917 is an apocalyptic number.

It is an amenable number.

646397917 is a deficient number, since it is larger than the sum of its proper divisors (95877443).

646397917 is a wasteful number, since it uses less digits than its factorization.

646397917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3092843.

The product of its digits is 1714608, while the sum is 52.

The square root of 646397917 is about 25424.3567666913. The cubic root of 646397917 is about 864.6360044236.

The spelling of 646397917 in words is "six hundred forty-six million, three hundred ninety-seven thousand, nine hundred seventeen".