215898161 has 2 divisors, whose sum is σ = 215898162. Its totient is φ = 215898160.

The previous prime is 215898143. The next prime is 215898191. The reversal of 215898161 is 161898512.

215898161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191296561 + 24601600 = 13831^2 + 4960^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215898161 is a prime.

It is a super-2 number, since 2×215898161² = 93224031846363842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215898191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107949080 + 107949081.

It is an arithmetic number, because the mean of its divisors is an integer number (107949081).

Almost surely, 2^215898161 is an apocalyptic number.

It is an amenable number.

215898161 is a deficient number, since it is larger than the sum of its proper divisors (1).

215898161 is an equidigital number, since it uses as much as digits as its factorization.

215898161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 41.

The square root of 215898161 is about 14693.4734150915. The cubic root of 215898161 is about 599.9056898064.

The spelling of 215898161 in words is "two hundred fifteen million, eight hundred ninety-eight thousand, one hundred sixty-one".