111221001 has 12 divisors (see below), whose sum is σ = 164995012. Its totient is φ = 72143136.

The previous prime is 111220999. The next prime is 111221023. The reversal of 111221001 is 100122111.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 80084601 + 31136400 = 8949^2 + 5580^2 .

It is not a de Polignac number, because 111221001 - 2¹ = 111220999 is a prime.

It is a super-2 number, since 2×111221001² = 24740222126884002, which contains 22 as substring.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111221051) 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, 166666 + ... + 167331.

Almost surely, 2^111221001 is an apocalyptic number.

It is an amenable number.

111221001 is a deficient number, since it is larger than the sum of its proper divisors (53774011).

111221001 is a wasteful number, since it uses less digits than its factorization.

111221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334040 (or 334037 counting only the distinct ones).

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

The square root of 111221001 is about 10546.1367808312. The cubic root of 111221001 is about 480.9082931940.

Adding to 111221001 its reverse (100122111), we get a palindrome (211343112).

The spelling of 111221001 in words is "one hundred eleven million, two hundred twenty-one thousand, one".