81292259 has 2 divisors, whose sum is σ = 81292260. Its totient is φ = 81292258.

The previous prime is 81292243. The next prime is 81292271. The reversal of 81292259 is 95229218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81292259 - 2⁴ = 81292243 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (81292229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40646129 + 40646130.

It is an arithmetic number, because the mean of its divisors is an integer number (40646130).

Almost surely, 2^81292259 is an apocalyptic number.

81292259 is a deficient number, since it is larger than the sum of its proper divisors (1).

81292259 is an equidigital number, since it uses as much as digits as its factorization.

81292259 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The square root of 81292259 is about 9016.2219914995. The cubic root of 81292259 is about 433.1946297037.

The spelling of 81292259 in words is "eighty-one million, two hundred ninety-two thousand, two hundred fifty-nine".