646396917 has 4 divisors (see below), whose sum is σ = 861862560. Its totient is φ = 430931276.

The previous prime is 646396913. The next prime is 646396937. The reversal of 646396917 is 719693646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 646396917 - 2² = 646396913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646396917.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646396913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107732817 + ... + 107732822.

It is an arithmetic number, because the mean of its divisors is an integer number (215465640).

Almost surely, 2^646396917 is an apocalyptic number.

It is an amenable number.

646396917 is a deficient number, since it is larger than the sum of its proper divisors (215465643).

646396917 is a wasteful number, since it uses less digits than its factorization.

646396917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215465642.

The product of its digits is 1469664, while the sum is 51.

The square root of 646396917 is about 25424.3371005027. The cubic root of 646396917 is about 864.6355585494.

The spelling of 646396917 in words is "six hundred forty-six million, three hundred ninety-six thousand, nine hundred seventeen".