2111131261 has 4 divisors (see below), whose sum is σ = 2111371452. Its totient is φ = 2110891072.

The previous prime is 2111131219. The next prime is 2111131277. The reversal of 2111131261 is 1621311112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 140304025 + 1970827236 = 11845^2 + 44394^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111131261 - 2¹¹ = 2111129213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111131361) 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, 106390 + ... + 124663.

It is an arithmetic number, because the mean of its divisors is an integer number (527842863).

Almost surely, 2^2111131261 is an apocalyptic number.

It is an amenable number.

2111131261 is a deficient number, since it is larger than the sum of its proper divisors (240191).

2111131261 is an equidigital number, since it uses as much as digits as its factorization.

2111131261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240190.

The product of its digits is 72, while the sum is 19.

The square root of 2111131261 is about 45947.0484470983. The cubic root of 2111131261 is about 1282.8377918268.

Adding to 2111131261 its reverse (1621311112), we get a palindrome (3732442373).

The spelling of 2111131261 in words is "two billion, one hundred eleven million, one hundred thirty-one thousand, two hundred sixty-one".