221215115 has 16 divisors (see below), whose sum is σ = 291810816. Its totient is φ = 159650400.

The previous prime is 221215073. The next prime is 221215129. The reversal of 221215115 is 511512122.

It is not a de Polignac number, because 221215115 - 2⁶ = 221215051 is a prime.

It is a super-2 number, since 2×221215115² = 97872254208926450, which contains 22 as substring.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 8147 + ... + 22556.

It is an arithmetic number, because the mean of its divisors is an integer number (18238176).

Almost surely, 2^221215115 is an apocalyptic number.

221215115 is a deficient number, since it is larger than the sum of its proper divisors (70595701).

221215115 is a wasteful number, since it uses less digits than its factorization.

221215115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30850.

The product of its digits is 200, while the sum is 20.

The square root of 221215115 is about 14873.3020879696. The cubic root of 221215115 is about 604.7904608689.

Adding to 221215115 its reverse (511512122), we get a palindrome (732727237).

The spelling of 221215115 in words is "two hundred twenty-one million, two hundred fifteen thousand, one hundred fifteen".