81226291 has 2 divisors, whose sum is σ = 81226292. Its totient is φ = 81226290.

The previous prime is 81226261. The next prime is 81226309. The reversal of 81226291 is 19262218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81226291 - 2⁵ = 81226259 is a prime.

It is not a weakly prime, because it can be changed into another prime (81226241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40613145 + 40613146.

It is an arithmetic number, because the mean of its divisors is an integer number (40613146).

Almost surely, 2^81226291 is an apocalyptic number.

81226291 is a deficient number, since it is larger than the sum of its proper divisors (1).

81226291 is an equidigital number, since it uses as much as digits as its factorization.

81226291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 31.

The square root of 81226291 is about 9012.5629540104. The cubic root of 81226291 is about 433.0774200327.

The spelling of 81226291 in words is "eighty-one million, two hundred twenty-six thousand, two hundred ninety-one".