1161211261 has 12 divisors (see below), whose sum is σ = 1351824768. Its totient is φ = 994566552.

The previous prime is 1161211253. The next prime is 1161211267. The reversal of 1161211261 is 1621121611.

It is a happy number.

It is not a de Polignac number, because 1161211261 - 2³ = 1161211253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161211267) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61620 + ... + 78226.

It is an arithmetic number, because the mean of its divisors is an integer number (112652064).

Almost surely, 2^1161211261 is an apocalyptic number.

It is an amenable number.

1161211261 is a deficient number, since it is larger than the sum of its proper divisors (190613507).

1161211261 is a wasteful number, since it uses less digits than its factorization.

1161211261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18048 (or 18041 counting only the distinct ones).

The product of its digits is 144, while the sum is 22.

The square root of 1161211261 is about 34076.5500161034. The cubic root of 1161211261 is about 1051.0831637224.

Adding to 1161211261 its reverse (1621121611), we get a palindrome (2782332872).

The spelling of 1161211261 in words is "one billion, one hundred sixty-one million, two hundred eleven thousand, two hundred sixty-one".