1123272161 has 20 divisors (see below), whose sum is σ = 1308563460. Its totient is φ = 960875520.

The previous prime is 1123272119. The next prime is 1123272173. The reversal of 1123272161 is 1612723211.

It can be written as a sum of positive squares in 2 ways, for example, as 307827025 + 815445136 = 17545^2 + 28556^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1123272161 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1123272161.

It is not an unprimeable number, because it can be changed into a prime (1123272181) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 246641 + ... + 251153.

It is an arithmetic number, because the mean of its divisors is an integer number (65428173).

Almost surely, 2^1123272161 is an apocalyptic number.

1123272161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1123272161 is a deficient number, since it is larger than the sum of its proper divisors (185291299).

1123272161 is an frugal number, since it uses more digits than its factorization.

1123272161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4574 (or 4541 counting only the distinct ones).

The product of its digits is 1008, while the sum is 26.

The square root of 1123272161 is about 33515.2526620343. The cubic root of 1123272161 is about 1039.5091868583.

Adding to 1123272161 its reverse (1612723211), we get a palindrome (2735995372).

The spelling of 1123272161 in words is "one billion, one hundred twenty-three million, two hundred seventy-two thousand, one hundred sixty-one".