646291 has 2 divisors, whose sum is σ = 646292. Its totient is φ = 646290.

The previous prime is 646273. The next prime is 646301. The reversal of 646291 is 192646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646291 - 2⁵ = 646259 is a prime.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (646271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323145 + 323146.

It is an arithmetic number, because the mean of its divisors is an integer number (323146).

2⁶⁴⁶²⁹¹ is an apocalyptic number.

646291 is a deficient number, since it is larger than the sum of its proper divisors (1).

646291 is an equidigital number, since it uses as much as digits as its factorization.

646291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 28.

The square root of 646291 is about 803.9222599232. The cubic root of 646291 is about 86.4588330288.

The spelling of 646291 in words is "six hundred forty-six thousand, two hundred ninety-one".