81827393 has 2 divisors, whose sum is σ = 81827394. Its totient is φ = 81827392.

The previous prime is 81827381. The next prime is 81827441. The reversal of 81827393 is 39372818.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69772609 + 12054784 = 8353^2 + 3472^2 .

It is a cyclic number.

It is not a de Polignac number, because 81827393 - 2¹⁸ = 81565249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81827393.

It is not a weakly prime, because it can be changed into another prime (81827303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40913696 + 40913697.

It is an arithmetic number, because the mean of its divisors is an integer number (40913697).

Almost surely, 2^81827393 is an apocalyptic number.

It is an amenable number.

81827393 is a deficient number, since it is larger than the sum of its proper divisors (1).

81827393 is an equidigital number, since it uses as much as digits as its factorization.

81827393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 81827393 is about 9045.8494902358. The cubic root of 81827393 is about 434.1431019532.

The spelling of 81827393 in words is "eighty-one million, eight hundred twenty-seven thousand, three hundred ninety-three".