81731827 has 2 divisors, whose sum is σ = 81731828. Its totient is φ = 81731826.

The previous prime is 81731821. The next prime is 81731849. The reversal of 81731827 is 72813718.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81731827 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81731821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40865913 + 40865914.

It is an arithmetic number, because the mean of its divisors is an integer number (40865914).

Almost surely, 2^81731827 is an apocalyptic number.

81731827 is a deficient number, since it is larger than the sum of its proper divisors (1).

81731827 is an equidigital number, since it uses as much as digits as its factorization.

81731827 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18816, while the sum is 37.

The square root of 81731827 is about 9040.5656349589. The cubic root of 81731827 is about 433.9740245803.

It can be divided in two parts, 8173 and 1827, that added together give a 4-th power (10000 = 10⁴).

The spelling of 81731827 in words is "eighty-one million, seven hundred thirty-one thousand, eight hundred twenty-seven".