10111221 has 12 divisors (see below), whose sum is σ = 14638572. Its totient is φ = 6725376.

The previous prime is 10111207. The next prime is 10111229. The reversal of 10111221 is 12211101.

It is a happy number.

10111221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 4536900 + 5574321 = 2130^2 + 2361^2 .

It is not a de Polignac number, because 10111221 - 2⁷ = 10111093 is a prime.

It is a super-2 number, since 2×10111221² = 204473580221682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10111229) 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, 4005 + ... + 6021.

It is an arithmetic number, because the mean of its divisors is an integer number (1219881).

Almost surely, 2^10111221 is an apocalyptic number.

It is an amenable number.

10111221 is a deficient number, since it is larger than the sum of its proper divisors (4527351).

10111221 is a wasteful number, since it uses less digits than its factorization.

10111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2580 (or 2577 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 10111221 is about 3179.8146172379. The cubic root of 10111221 is about 216.2392539238.

Adding to 10111221 its reverse (12211101), we get a palindrome (22322322).

The spelling of 10111221 in words is "ten million, one hundred eleven thousand, two hundred twenty-one".