1121278121 has 4 divisors (see below), whose sum is σ = 1123700352. Its totient is φ = 1118855892.

The previous prime is 1121278073. The next prime is 1121278139. The reversal of 1121278121 is 1218721211.

It is a happy number.

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: 1218721211 = 17 ⋅71689483.

It is a cyclic number.

It is not a de Polignac number, because 1121278121 - 2²² = 1117083817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1121278021) 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, 1210421 + ... + 1211346.

It is an arithmetic number, because the mean of its divisors is an integer number (280925088).

Almost surely, 2^1121278121 is an apocalyptic number.

It is an amenable number.

1121278121 is a deficient number, since it is larger than the sum of its proper divisors (2422231).

1121278121 is an equidigital number, since it uses as much as digits as its factorization.

1121278121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2422230.

The product of its digits is 448, while the sum is 26.

The square root of 1121278121 is about 33485.4912014144. The cubic root of 1121278121 is about 1038.8937080382.

Adding to 1121278121 its reverse (1218721211), we get a palindrome (2339999332).

The spelling of 1121278121 in words is "one billion, one hundred twenty-one million, two hundred seventy-eight thousand, one hundred twenty-one".