1000221121 has 4 divisors (see below), whose sum is σ = 1000735744. Its totient is φ = 999706500.

The previous prime is 1000221109. The next prime is 1000221137. The reversal of 1000221121 is 1211220001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1211220001 = 43 ⋅28167907.

It is a cyclic number.

It is not a de Polignac number, because 1000221121 - 2¹⁹ = 999696833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1000221098 and 1000221107.

It is not an unprimeable number, because it can be changed into a prime (1000221181) 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, 254385 + ... + 258286.

It is an arithmetic number, because the mean of its divisors is an integer number (250183936).

Almost surely, 2^1000221121 is an apocalyptic number.

It is an amenable number.

1000221121 is a deficient number, since it is larger than the sum of its proper divisors (514623).

1000221121 is an equidigital number, since it uses as much as digits as its factorization.

1000221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514622.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1000221121 is about 31626.2726384252. The cubic root of 1000221121 is about 1000.0737015679.

Adding to 1000221121 its reverse (1211220001), we get a palindrome (2211441122).

The spelling of 1000221121 in words is "one billion, two hundred twenty-one thousand, one hundred twenty-one".