1002111221 has 4 divisors (see below), whose sum is σ = 1002189132. Its totient is φ = 1002033312.

The previous prime is 1002111203. The next prime is 1002111277. The reversal of 1002111221 is 1221112001.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 594676996 + 407434225 = 24386^2 + 20185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002111221 - 2⁶ = 1002111157 is a prime.

It is a super-2 number, since 2×1002111221² = 2008453798508221682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002113221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14576 + ... + 47081.

It is an arithmetic number, because the mean of its divisors is an integer number (250547283).

Almost surely, 2^1002111221 is an apocalyptic number.

It is an amenable number.

1002111221 is a deficient number, since it is larger than the sum of its proper divisors (77911).

1002111221 is an equidigital number, since it uses as much as digits as its factorization.

1002111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77910.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1002111221 is about 31656.1403364339. The cubic root of 1002111221 is about 1000.7032456629.

Adding to 1002111221 its reverse (1221112001), we get a palindrome (2223223222).

The spelling of 1002111221 in words is "one billion, two million, one hundred eleven thousand, two hundred twenty-one".