1121511665 has 4 divisors (see below), whose sum is σ = 1345814004. Its totient is φ = 897209328.

The previous prime is 1121511661. The next prime is 1121511667. The reversal of 1121511665 is 5661151211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5661151211 = 31 ⋅182617781.

It can be written as a sum of positive squares in 2 ways, for example, as 392079601 + 729432064 = 19801^2 + 27008^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121511665 - 2² = 1121511661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1121511661) 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, 112151162 + ... + 112151171.

It is an arithmetic number, because the mean of its divisors is an integer number (336453501).

Almost surely, 2^1121511665 is an apocalyptic number.

It is an amenable number.

1121511665 is a deficient number, since it is larger than the sum of its proper divisors (224302339).

1121511665 is an equidigital number, since it uses as much as digits as its factorization.

1121511665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224302338.

The product of its digits is 1800, while the sum is 29.

The square root of 1121511665 is about 33488.9782615117. The cubic root of 1121511665 is about 1038.9658312532.

Adding to 1121511665 its reverse (5661151211), we get a palindrome (6782662876).

The spelling of 1121511665 in words is "one billion, one hundred twenty-one million, five hundred eleven thousand, six hundred sixty-five".