215113221 has 6 divisors (see below), whose sum is σ = 310719110. Its totient is φ = 143408808.

The previous prime is 215113207. The next prime is 215113253. The reversal of 215113221 is 122311512.

It can be written as a sum of positive squares in only one way, i.e., 155900196 + 59213025 = 12486^2 + 7695^2 .

It is not a de Polignac number, because 215113221 - 2¹⁷ = 214982149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 215113194 and 215113203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215113021) 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 5 ways as a sum of consecutive naturals, for example, 11950726 + ... + 11950743.

Almost surely, 2^215113221 is an apocalyptic number.

It is an amenable number.

215113221 is a deficient number, since it is larger than the sum of its proper divisors (95605889).

215113221 is a wasteful number, since it uses less digits than its factorization.

215113221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23901475 (or 23901472 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 215113221 is about 14666.7385945206. The cubic root of 215113221 is about 599.1777821109.

Adding to 215113221 its reverse (122311512), we get a palindrome (337424733).

The spelling of 215113221 in words is "two hundred fifteen million, one hundred thirteen thousand, two hundred twenty-one".