81857341 has 2 divisors, whose sum is σ = 81857342. Its totient is φ = 81857340.

The previous prime is 81857323. The next prime is 81857353. The reversal of 81857341 is 14375818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81830116 + 27225 = 9046^2 + 165^2 .

It is a cyclic number.

It is not a de Polignac number, because 81857341 - 2⁷ = 81857213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81857341.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81857311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40928670 + 40928671.

It is an arithmetic number, because the mean of its divisors is an integer number (40928671).

Almost surely, 2^81857341 is an apocalyptic number.

It is an amenable number.

81857341 is a deficient number, since it is larger than the sum of its proper divisors (1).

81857341 is an equidigital number, since it uses as much as digits as its factorization.

81857341 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26880, while the sum is 37.

The square root of 81857341 is about 9047.5046836130. The cubic root of 81857341 is about 434.1960594910.

The spelling of 81857341 in words is "eighty-one million, eight hundred fifty-seven thousand, three hundred forty-one".