1121211221 has 4 divisors (see below), whose sum is σ = 1207458252. Its totient is φ = 1034964192.

The previous prime is 1121211127. The next prime is 1121211229. The reversal of 1121211221 is 1221121211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221121211 = 5879 ⋅207709.

It can be written as a sum of positive squares in 2 ways, for example, as 534118321 + 587092900 = 23111^2 + 24230^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121211221 - 2²² = 1117016917 is a prime.

It is a super-2 number, since 2×1121211221² = 2514229204192621682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1121211196 and 1121211205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121211229) 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, 43123496 + ... + 43123521.

It is an arithmetic number, because the mean of its divisors is an integer number (301864563).

Almost surely, 2^1121211221 is an apocalyptic number.

It is an amenable number.

1121211221 is a deficient number, since it is larger than the sum of its proper divisors (86247031).

1121211221 is an equidigital number, since it uses as much as digits as its factorization.

1121211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86247030.

The product of its digits is 16, while the sum is 14.

The square root of 1121211221 is about 33484.4922464116. The cubic root of 1121211221 is about 1038.8730460900.

Adding to 1121211221 its reverse (1221121211), we get a palindrome (2342332432).

The spelling of 1121211221 in words is "one billion, one hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".