1220240121 has 4 divisors (see below), whose sum is σ = 1626986832. Its totient is φ = 813493412.

The previous prime is 1220240071. The next prime is 1220240143. The reversal of 1220240121 is 1210420221.

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: 1210420221 = 3 ⋅403473407.

It is a cyclic number.

It is not a de Polignac number, because 1220240121 - 2¹¹ = 1220238073 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1220240121.

It is not an unprimeable number, because it can be changed into a prime (1220240191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203373351 + ... + 203373356.

It is an arithmetic number, because the mean of its divisors is an integer number (406746708).

Almost surely, 2^1220240121 is an apocalyptic number.

It is an amenable number.

1220240121 is a deficient number, since it is larger than the sum of its proper divisors (406746711).

1220240121 is an equidigital number, since it uses as much as digits as its factorization.

1220240121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406746710.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 1220240121 is about 34931.9355461446. The cubic root of 1220240121 is about 1068.5998283992.

Adding to 1220240121 its reverse (1210420221), we get a palindrome (2430660342).

The spelling of 1220240121 in words is "one billion, two hundred twenty million, two hundred forty thousand, one hundred twenty-one".