1121620165 has 4 divisors (see below), whose sum is σ = 1345944204. Its totient is φ = 897296128.

The previous prime is 1121620121. The next prime is 1121620189. The reversal of 1121620165 is 5610261211.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5610261211 = 7243 ⋅774577.

It can be written as a sum of positive squares in 2 ways, for example, as 346220449 + 775399716 = 18607^2 + 27846^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1121620165 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112162012 + ... + 112162021.

It is an arithmetic number, because the mean of its divisors is an integer number (336486051).

Almost surely, 2^1121620165 is an apocalyptic number.

It is an amenable number.

1121620165 is a deficient number, since it is larger than the sum of its proper divisors (224324039).

1121620165 is an equidigital number, since it uses as much as digits as its factorization.

1121620165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224324038.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 1121620165 is about 33490.5981582891. The cubic root of 1121620165 is about 1038.9993348898. Note that the first 3 decimals are identical.

Adding to 1121620165 its reverse (5610261211), we get a palindrome (6731881376).

The spelling of 1121620165 in words is "one billion, one hundred twenty-one million, six hundred twenty thousand, one hundred sixty-five".