81457 has 2 divisors, whose sum is σ = 81458. Its totient is φ = 81456.

The previous prime is 81439. The next prime is 81463. The reversal of 81457 is 75418.

81457 is nontrivially palindromic in base 16.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57121 + 24336 = 239^2 + 156^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81457 is a prime.

It is not a weakly prime, because it can be changed into another prime (81157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40728 + 40729.

It is an arithmetic number, because the mean of its divisors is an integer number (40729).

2⁸¹⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

81457 is a deficient number, since it is larger than the sum of its proper divisors (1).

81457 is an equidigital number, since it uses as much as digits as its factorization.

81457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1120, while the sum is 25.

The square root of 81457 is about 285.4067273209. The cubic root of 81457 is about 43.3487059200.

The spelling of 81457 in words is "eighty-one thousand, four hundred fifty-seven".