1221030121 has 4 divisors (see below), whose sum is σ = 1221101200. Its totient is φ = 1220959044.

The previous prime is 1221030119. The next prime is 1221030137. The reversal of 1221030121 is 1210301221.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1210301221 = 2917 ⋅414913.

It is a cyclic number.

It is not a de Polignac number, because 1221030121 - 2¹ = 1221030119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221030191) 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, 8050 + ... + 50068.

It is an arithmetic number, because the mean of its divisors is an integer number (305275300).

Almost surely, 2^1221030121 is an apocalyptic number.

It is an amenable number.

1221030121 is a deficient number, since it is larger than the sum of its proper divisors (71079).

1221030121 is an equidigital number, since it uses as much as digits as its factorization.

1221030121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71078.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1221030121 is about 34943.2414209100. The cubic root of 1221030121 is about 1068.8303873235.

Adding to 1221030121 its reverse (1210301221), we get a palindrome (2431331342).

It can be divided in two parts, 1 and 221030121, that added together give a palindrome (221030122).

The spelling of 1221030121 in words is "one billion, two hundred twenty-one million, thirty thousand, one hundred twenty-one".