215888121 has 12 divisors (see below), whose sum is σ = 313753648. Its totient is φ = 143041464.

The previous prime is 215888111. The next prime is 215888129. The reversal of 215888121 is 121888512.

It is not a de Polignac number, because 215888121 - 2¹⁷ = 215757049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215888129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72115 + ... + 75048.

Almost surely, 2^215888121 is an apocalyptic number.

It is an amenable number.

215888121 is a deficient number, since it is larger than the sum of its proper divisors (97865527).

215888121 is a wasteful number, since it uses less digits than its factorization.

215888121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147332 (or 147329 counting only the distinct ones).

The product of its digits is 10240, while the sum is 36.

The square root of 215888121 is about 14693.1317628340. The cubic root of 215888121 is about 599.8963904428.

The spelling of 215888121 in words is "two hundred fifteen million, eight hundred eighty-eight thousand, one hundred twenty-one".