81111269 has 2 divisors, whose sum is σ = 81111270. Its totient is φ = 81111268.

The previous prime is 81111263. The next prime is 81111313. The reversal of 81111269 is 96211118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56806369 + 24304900 = 7537^2 + 4930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81111269 is a prime.

It is a super-2 number, since 2×81111269² = 13158075917580722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81111263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40555634 + 40555635.

It is an arithmetic number, because the mean of its divisors is an integer number (40555635).

Almost surely, 2^81111269 is an apocalyptic number.

It is an amenable number.

81111269 is a deficient number, since it is larger than the sum of its proper divisors (1).

81111269 is an equidigital number, since it uses as much as digits as its factorization.

81111269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 29.

The square root of 81111269 is about 9006.1794896615. The cubic root of 81111269 is about 432.8729010196.

The spelling of 81111269 in words is "eighty-one million, one hundred eleven thousand, two hundred sixty-nine".