1121221221 has 16 divisors (see below), whose sum is σ = 1511267328. Its totient is φ = 739350000.

The previous prime is 1121221183. The next prime is 1121221223. The reversal of 1121221221 is 1221221211.

It is not a de Polignac number, because 1121221221 - 2¹³ = 1121213029 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1121221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121221223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 238746 + ... + 243396.

It is an arithmetic number, because the mean of its divisors is an integer number (94454208).

Almost surely, 2^1121221221 is an apocalyptic number.

It is an amenable number.

1121221221 is a deficient number, since it is larger than the sum of its proper divisors (390046107).

1121221221 is a wasteful number, since it uses less digits than its factorization.

1121221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5512.

The product of its digits is 32, while the sum is 15.

The square root of 1121221221 is about 33484.6415689343. The cubic root of 1121221221 is about 1038.8761346248.

Adding to 1121221221 its reverse (1221221211), we get a palindrome (2342442432).

The spelling of 1121221221 in words is "one billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".