646215 has 16 divisors (see below), whose sum is σ = 1051008. Its totient is φ = 338976.

The previous prime is 646199. The next prime is 646237. The reversal of 646215 is 512646.

It is not a de Polignac number, because 646215 - 2⁴ = 646199 is a prime.

It is a nialpdrome in base 15.

It is a congruent number.

It is an unprimeable number.

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 in 15 ways as a sum of consecutive naturals, for example, 684 + ... + 1326.

It is an arithmetic number, because the mean of its divisors is an integer number (65688).

2⁶⁴⁶²¹⁵ is an apocalyptic number.

646215 is a deficient number, since it is larger than the sum of its proper divisors (404793).

646215 is a wasteful number, since it uses less digits than its factorization.

646215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718.

The product of its digits is 1440, while the sum is 24.

The square root of 646215 is about 803.8749902814. The cubic root of 646215 is about 86.4554438801.

It can be divided in two parts, 646 and 215, that added together give a triangular number (861 = T₄₁).

The spelling of 646215 in words is "six hundred forty-six thousand, two hundred fifteen".