215841681 has 12 divisors (see below), whose sum is σ = 340114320. Its totient is φ = 130813080.

The previous prime is 215841679. The next prime is 215841709. The reversal of 215841681 is 186148512.

It is not a de Polignac number, because 215841681 - 2¹ = 215841679 is a prime.

It is a super-2 number, since 2×215841681² = 93175262513811522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (215841641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1090011 + ... + 1090208.

It is an arithmetic number, because the mean of its divisors is an integer number (28342860).

Almost surely, 2^215841681 is an apocalyptic number.

It is an amenable number.

215841681 is a deficient number, since it is larger than the sum of its proper divisors (124272639).

215841681 is a wasteful number, since it uses less digits than its factorization.

215841681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2180236 (or 2180233 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 215841681 is about 14691.5513476283. The cubic root of 215841681 is about 599.8533725035.

The spelling of 215841681 in words is "two hundred fifteen million, eight hundred forty-one thousand, six hundred eighty-one".