646751 has 12 divisors (see below), whose sum is σ = 767448. Its totient is φ = 543312.

The previous prime is 646721. The next prime is 646757. The reversal of 646751 is 157646.

It is not a de Polignac number, because 646751 - 2⁶ = 646687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646751.

It is not an unprimeable number, because it can be changed into a prime (646757) 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, 3185 + ... + 3381.

It is an arithmetic number, because the mean of its divisors is an integer number (63954).

2⁶⁴⁶⁷⁵¹ is an apocalyptic number.

646751 is a deficient number, since it is larger than the sum of its proper divisors (120697).

646751 is a wasteful number, since it uses less digits than its factorization.

646751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 271 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 646751 is about 804.2083063485. The cubic root of 646751 is about 86.4793406285.

The spelling of 646751 in words is "six hundred forty-six thousand, seven hundred fifty-one".