1111121221 has 4 divisors (see below), whose sum is σ = 1269852832. Its totient is φ = 952389612.

The previous prime is 1111121201. The next prime is 1111121227. The reversal of 1111121221 is 1221211111.

It is a happy number.

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: 1221211111 = 19 ⋅64274269.

It is a cyclic number.

It is not a de Polignac number, because 1111121221 - 2⁹ = 1111120709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111121227) 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, 79365795 + ... + 79365808.

It is an arithmetic number, because the mean of its divisors is an integer number (317463208).

Almost surely, 2^1111121221 is an apocalyptic number.

It is an amenable number.

1111121221 is a deficient number, since it is larger than the sum of its proper divisors (158731611).

1111121221 is an equidigital number, since it uses as much as digits as its factorization.

1111121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158731610.

The product of its digits is 8, while the sum is 13.

The square root of 1111121221 is about 33333.4849813217. The cubic root of 1111121221 is about 1035.7473100193.

Adding to 1111121221 its reverse (1221211111), we get a palindrome (2332332332).

The spelling of 1111121221 in words is "one billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".