646644215 has 32 divisors (see below), whose sum is σ = 952280064. Its totient is φ = 411425280.

The previous prime is 646644209. The next prime is 646644223. The reversal of 646644215 is 512446646.

646644215 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 646644215 - 2¹⁴ = 646627831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34592 + ... + 49898.

It is an arithmetic number, because the mean of its divisors is an integer number (29758752).

Almost surely, 2^646644215 is an apocalyptic number.

646644215 is a deficient number, since it is larger than the sum of its proper divisors (305635849).

646644215 is a wasteful number, since it uses less digits than its factorization.

646644215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15407.

The product of its digits is 138240, while the sum is 38.

The square root of 646644215 is about 25429.2000464033. The cubic root of 646644215 is about 864.7458083440.

The spelling of 646644215 in words is "six hundred forty-six million, six hundred forty-four thousand, two hundred fifteen".