1220121211 has 4 divisors (see below), whose sum is σ = 1231967152. Its totient is φ = 1208275272.

The previous prime is 1220121169. The next prime is 1220121247. The reversal of 1220121211 is 1121210221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1121210221 = 2531 ⋅442991.

It is a cyclic number.

It is not a de Polignac number, because 1220121211 - 2⁷ = 1220121083 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220121191 and 1220121200.

It is not an unprimeable number, because it can be changed into a prime (1220121251) 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, 5922816 + ... + 5923021.

It is an arithmetic number, because the mean of its divisors is an integer number (307991788).

Almost surely, 2^1220121211 is an apocalyptic number.

1220121211 is a deficient number, since it is larger than the sum of its proper divisors (11845941).

1220121211 is a wasteful number, since it uses less digits than its factorization.

1220121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11845940.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1220121211 is about 34930.2334804679. The cubic root of 1220121211 is about 1068.5651162877.

Adding to 1220121211 its reverse (1121210221), we get a palindrome (2341331432).

The spelling of 1220121211 in words is "one billion, two hundred twenty million, one hundred twenty-one thousand, two hundred eleven".