2011223261 has 2 divisors, whose sum is σ = 2011223262. Its totient is φ = 2011223260.

The previous prime is 2011223257. The next prime is 2011223273. The reversal of 2011223261 is 1623221102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1790136100 + 221087161 = 42310^2 + 14869^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011223261 - 2² = 2011223257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2011223281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1005611630 + 1005611631.

It is an arithmetic number, because the mean of its divisors is an integer number (1005611631).

Almost surely, 2^2011223261 is an apocalyptic number.

It is an amenable number.

2011223261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011223261 is an equidigital number, since it uses as much as digits as its factorization.

2011223261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 2011223261 is about 44846.6638781526. The cubic root of 2011223261 is about 1262.2733923382.

Adding to 2011223261 its reverse (1623221102), we get a palindrome (3634444363).

The spelling of 2011223261 in words is "two billion, eleven million, two hundred twenty-three thousand, two hundred sixty-one".