81739271 has 2 divisors, whose sum is σ = 81739272. Its totient is φ = 81739270.

The previous prime is 81739267. The next prime is 81739277. The reversal of 81739271 is 17293718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81739271 - 2² = 81739267 is a prime.

It is a super-2 number, since 2×81739271² = 13362616847222882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81739277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40869635 + 40869636.

It is an arithmetic number, because the mean of its divisors is an integer number (40869636).

Almost surely, 2^81739271 is an apocalyptic number.

81739271 is a deficient number, since it is larger than the sum of its proper divisors (1).

81739271 is an equidigital number, since it uses as much as digits as its factorization.

81739271 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 38.

The square root of 81739271 is about 9040.9773254887. The cubic root of 81739271 is about 433.9871993931.

The spelling of 81739271 in words is "eighty-one million, seven hundred thirty-nine thousand, two hundred seventy-one".