81486281 has 6 divisors (see below), whose sum is σ = 83055630. Its totient is φ = 79946048.

The previous prime is 81486241. The next prime is 81486359. The reversal of 81486281 is 18268418.

It can be written as a sum of positive squares in 3 ways, for example, as 12845056 + 68641225 = 3584^2 + 8285^2 .

It is not a de Polignac number, because 81486281 - 2¹⁸ = 81224137 is a prime.

It is a super-2 number, since 2×81486281² = 13280027982421922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81486211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11696 + ... + 17313.

It is an arithmetic number, because the mean of its divisors is an integer number (13842605).

Almost surely, 2^81486281 is an apocalyptic number.

It is an amenable number.

81486281 is a deficient number, since it is larger than the sum of its proper divisors (1569349).

81486281 is an equidigital number, since it uses as much as digits as its factorization.

81486281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29115 (or 29062 counting only the distinct ones).

The product of its digits is 24576, while the sum is 38.

The square root of 81486281 is about 9026.9751855203. The cubic root of 81486281 is about 433.5389942249.

The spelling of 81486281 in words is "eighty-one million, four hundred eighty-six thousand, two hundred eighty-one".