215636161 has 4 divisors (see below), whose sum is σ = 232223572. Its totient is φ = 199048752.

The previous prime is 215636147. The next prime is 215636167. The reversal of 215636161 is 161636512.

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 82464561 + 133171600 = 9081^2 + 11540^2 .

It is a cyclic number.

It is not a de Polignac number, because 215636161 - 2⁵ = 215636129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215636167) by changing a digit.

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, 8293686 + ... + 8293711.

It is an arithmetic number, because the mean of its divisors is an integer number (58055893).

Almost surely, 2^215636161 is an apocalyptic number.

It is an amenable number.

215636161 is a deficient number, since it is larger than the sum of its proper divisors (16587411).

215636161 is a wasteful number, since it uses less digits than its factorization.

215636161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16587410.

The product of its digits is 6480, while the sum is 31.

The square root of 215636161 is about 14684.5551856364. Note that the first 3 decimals coincide. The cubic root of 215636161 is about 599.6629227040.

The spelling of 215636161 in words is "two hundred fifteen million, six hundred thirty-six thousand, one hundred sixty-one".