1121440561 has 4 divisors (see below), whose sum is σ = 1121782372. Its totient is φ = 1121098752.

The previous prime is 1121440543. The next prime is 1121440583. The reversal of 1121440561 is 1650441211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1650441211 = 2273 ⋅726107.

It can be written as a sum of positive squares in 2 ways, for example, as 558849600 + 562590961 = 23640^2 + 23719^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121440561 - 2⁷ = 1121440433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1121440361) 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, 165936 + ... + 172561.

It is an arithmetic number, because the mean of its divisors is an integer number (280445593).

Almost surely, 2^1121440561 is an apocalyptic number.

It is an amenable number.

1121440561 is a deficient number, since it is larger than the sum of its proper divisors (341811).

1121440561 is an equidigital number, since it uses as much as digits as its factorization.

1121440561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341810.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1121440561 is about 33487.9166416784. The cubic root of 1121440561 is about 1038.9438739284.

Adding to 1121440561 its reverse (1650441211), we get a palindrome (2771881772).

The spelling of 1121440561 in words is "one billion, one hundred twenty-one million, four hundred forty thousand, five hundred sixty-one".