1161323261 has 32 divisors (see below), whose sum is σ = 1440011520. Its totient is φ = 914006016.

The previous prime is 1161323257. The next prime is 1161323281. The reversal of 1161323261 is 1623231611.

It is not a de Polignac number, because 1161323261 - 2² = 1161323257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1161323261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161323281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900305 + ... + 901593.

It is an arithmetic number, because the mean of its divisors is an integer number (45000360).

Almost surely, 2^1161323261 is an apocalyptic number.

It is an amenable number.

1161323261 is a deficient number, since it is larger than the sum of its proper divisors (278688259).

1161323261 is a wasteful number, since it uses less digits than its factorization.

1161323261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1493.

The product of its digits is 1296, while the sum is 26.

The square root of 1161323261 is about 34078.1933353281. The cubic root of 1161323261 is about 1051.1169553139.

Adding to 1161323261 its reverse (1623231611), we get a palindrome (2784554872).

The spelling of 1161323261 in words is "one billion, one hundred sixty-one million, three hundred twenty-three thousand, two hundred sixty-one".