1201221121 has 4 divisors (see below), whose sum is σ = 1206513072. Its totient is φ = 1195929172.

The previous prime is 1201221107. The next prime is 1201221127. The reversal of 1201221121 is 1211221021.

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: 1211221021 = 71 ⋅17059451.

It is a cyclic number.

It is not a de Polignac number, because 1201221121 - 2²¹ = 1199123969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1201221127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2645635 + ... + 2646088.

It is an arithmetic number, because the mean of its divisors is an integer number (301628268).

Almost surely, 2^1201221121 is an apocalyptic number.

It is an amenable number.

1201221121 is a deficient number, since it is larger than the sum of its proper divisors (5291951).

1201221121 is an equidigital number, since it uses as much as digits as its factorization.

1201221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5291950.

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

The square root of 1201221121 is about 34658.6370332129. The cubic root of 1201221121 is about 1063.0189010674.

Adding to 1201221121 its reverse (1211221021), we get a palindrome (2412442142).

It can be divided in two parts, 12012 and 21121, that added together give a palindrome (33133).

The spelling of 1201221121 in words is "one billion, two hundred one million, two hundred twenty-one thousand, one hundred twenty-one".