646268391 has 12 divisors (see below), whose sum is σ = 937134432. Its totient is φ = 429167616.

The previous prime is 646268387. The next prime is 646268419. The reversal of 646268391 is 193862646.

646268391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 646268391 - 2² = 646268387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646268291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 137391 + ... + 142016.

It is an arithmetic number, because the mean of its divisors is an integer number (78094536).

Almost surely, 2^646268391 is an apocalyptic number.

646268391 is a deficient number, since it is larger than the sum of its proper divisors (290866041).

646268391 is a wasteful number, since it uses less digits than its factorization.

646268391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279670 (or 279667 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 646268391 is about 25421.8093573215. The cubic root of 646268391 is about 864.5782482946.

The spelling of 646268391 in words is "six hundred forty-six million, two hundred sixty-eight thousand, three hundred ninety-one".