646281 has 6 divisors (see below), whose sum is σ = 933530. Its totient is φ = 430848.

The previous prime is 646273. The next prime is 646291. The reversal of 646281 is 182646.

646281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 435600 + 210681 = 660^2 + 459^2 .

It is not a de Polignac number, because 646281 - 2³ = 646273 is a prime.

It is a super-2 number, since 2×646281² = 835358261922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646281.

It is not an unprimeable number, because it can be changed into a prime (646271) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35896 + ... + 35913.

2⁶⁴⁶²⁸¹ is an apocalyptic number.

It is an amenable number.

646281 is a deficient number, since it is larger than the sum of its proper divisors (287249).

646281 is a wasteful number, since it uses less digits than its factorization.

646281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71815 (or 71812 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 646281 is about 803.9160403923. The cubic root of 646281 is about 86.4583871034.

The spelling of 646281 in words is "six hundred forty-six thousand, two hundred eighty-one".