81255836 has 12 divisors (see below), whose sum is σ = 146784960. Its totient is φ = 39317280.

The previous prime is 81255829. The next prime is 81255857. The reversal of 81255836 is 63855218.

It is a self number, because there is not a number n which added to its sum of digits gives 81255836.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327521 + ... + 327768.

It is an arithmetic number, because the mean of its divisors is an integer number (12232080).

Almost surely, 2^81255836 is an apocalyptic number.

It is an amenable number.

81255836 is a deficient number, since it is larger than the sum of its proper divisors (65529124).

81255836 is a wasteful number, since it uses less digits than its factorization.

81255836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655324 (or 655322 counting only the distinct ones).

The product of its digits is 57600, while the sum is 38.

The square root of 81255836 is about 9014.2019058816. The cubic root of 81255836 is about 433.1299224148.

The spelling of 81255836 in words is "eighty-one million, two hundred fifty-five thousand, eight hundred thirty-six".