221215215 has 16 divisors (see below), whose sum is σ = 381171168. Its totient is φ = 108905856.

The previous prime is 221215207. The next prime is 221215223. The reversal of 221215215 is 512512122.

It is an interprime number because it is at equal distance from previous prime (221215207) and next prime (221215223).

It is not a de Polignac number, because 221215215 - 2³ = 221215207 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221215191 and 221215200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 567024 + ... + 567413.

It is an arithmetic number, because the mean of its divisors is an integer number (23823198).

Almost surely, 2^221215215 is an apocalyptic number.

221215215 is a deficient number, since it is larger than the sum of its proper divisors (159955953).

221215215 is a wasteful number, since it uses less digits than its factorization.

221215215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134458.

The product of its digits is 400, while the sum is 21.

The square root of 221215215 is about 14873.3054496975. The cubic root of 221215215 is about 604.7905520005.

Adding to 221215215 its reverse (512512122), we get a palindrome (733727337).

The spelling of 221215215 in words is "two hundred twenty-one million, two hundred fifteen thousand, two hundred fifteen".