81286397 has 2 divisors, whose sum is σ = 81286398. Its totient is φ = 81286396.

The previous prime is 81286363. The next prime is 81286411. The reversal of 81286397 is 79368218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67551961 + 13734436 = 8219^2 + 3706^2 .

It is a cyclic number.

It is not a de Polignac number, because 81286397 - 2¹⁸ = 81024253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81286357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40643198 + 40643199.

It is an arithmetic number, because the mean of its divisors is an integer number (40643199).

Almost surely, 2^81286397 is an apocalyptic number.

It is an amenable number.

81286397 is a deficient number, since it is larger than the sum of its proper divisors (1).

81286397 is an equidigital number, since it uses as much as digits as its factorization.

81286397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 81286397 is about 9015.8969049119. The cubic root of 81286397 is about 433.1842168715.

The spelling of 81286397 in words is "eighty-one million, two hundred eighty-six thousand, three hundred ninety-seven".