1221122121 has 8 divisors (see below), whose sum is σ = 1723937184. Its totient is φ = 766194240.

The previous prime is 1221122099. The next prime is 1221122159. The reversal of 1221122121 is 1212211221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221122121 - 2¹⁸ = 1220859977 is a prime.

It is a super-2 number, since 2×1221122121² = 2982278468791077282, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221122121.

It is not an unprimeable number, because it can be changed into a prime (1221122321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11971735 + ... + 11971836.

It is an arithmetic number, because the mean of its divisors is an integer number (215492148).

Almost surely, 2^1221122121 is an apocalyptic number.

It is an amenable number.

1221122121 is a deficient number, since it is larger than the sum of its proper divisors (502815063).

1221122121 is a wasteful number, since it uses less digits than its factorization.

1221122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23943591.

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

The square root of 1221122121 is about 34944.5578166329. The cubic root of 1221122121 is about 1068.8572307579.

Adding to 1221122121 its reverse (1212211221), we get a palindrome (2433333342).

The spelling of 1221122121 in words is "one billion, two hundred twenty-one million, one hundred twenty-two thousand, one hundred twenty-one".