81807255 has 48 divisors (see below), whose sum is σ = 150433920. Its totient is φ = 41010624.

The previous prime is 81807223. The next prime is 81807263. The reversal of 81807255 is 55270818.

It is not a de Polignac number, because 81807255 - 2⁵ = 81807223 is a prime.

It is a congruent number.

It is an unprimeable number.

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 in 47 ways as a sum of consecutive naturals, for example, 139072 + ... + 139658.

It is an arithmetic number, because the mean of its divisors is an integer number (3134040).

Almost surely, 2^81807255 is an apocalyptic number.

81807255 is a deficient number, since it is larger than the sum of its proper divisors (68626665).

81807255 is a wasteful number, since it uses less digits than its factorization.

81807255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780 (or 777 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 81807255 is about 9044.7363145644. The cubic root of 81807255 is about 434.1074843327.

The spelling of 81807255 in words is "eighty-one million, eight hundred seven thousand, two hundred fifty-five".