216164645 has 4 divisors (see below), whose sum is σ = 259397580. Its totient is φ = 172931712.

The previous prime is 216164623. The next prime is 216164651. The reversal of 216164645 is 546461612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 171662404 + 44502241 = 13102^2 + 6671^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216164645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21616460 + ... + 21616469.

It is an arithmetic number, because the mean of its divisors is an integer number (64849395).

Almost surely, 2^216164645 is an apocalyptic number.

It is an amenable number.

216164645 is a deficient number, since it is larger than the sum of its proper divisors (43232935).

216164645 is an equidigital number, since it uses as much as digits as its factorization.

216164645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43232934.

The product of its digits is 34560, while the sum is 35.

The square root of 216164645 is about 14702.5387263561. The cubic root of 216164645 is about 600.1524103559.

The spelling of 216164645 in words is "two hundred sixteen million, one hundred sixty-four thousand, six hundred forty-five".