10215221 has 4 divisors (see below), whose sum is σ = 10567500. Its totient is φ = 9862944.

The previous prime is 10215211. The next prime is 10215229. The reversal of 10215221 is 12251201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2592100 + 7623121 = 1610^2 + 2761^2 .

It is a cyclic number.

It is not a de Polignac number, because 10215221 - 2⁶ = 10215157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10215196 and 10215205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10215229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176096 + ... + 176153.

It is an arithmetic number, because the mean of its divisors is an integer number (2641875).

Almost surely, 2^10215221 is an apocalyptic number.

It is an amenable number.

10215221 is a deficient number, since it is larger than the sum of its proper divisors (352279).

10215221 is an equidigital number, since it uses as much as digits as its factorization.

10215221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352278.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 10215221 is about 3196.1259361921. The cubic root of 10215221 is about 216.9781101607.

Adding to 10215221 its reverse (12251201), we get a palindrome (22466422).

The spelling of 10215221 in words is "ten million, two hundred fifteen thousand, two hundred twenty-one".