81288255 has 32 divisors (see below), whose sum is σ = 133152768. Its totient is φ = 42336000.

The previous prime is 81288227. The next prime is 81288257. The reversal of 81288255 is 55288218.

It is a Cunningham number, because it is equal to 9016²-1.

It is not a de Polignac number, because 81288255 - 2⁶ = 81288191 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81288257) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 134955 + ... + 135555.

It is an arithmetic number, because the mean of its divisors is an integer number (4161024).

Almost surely, 2^81288255 is an apocalyptic number.

81288255 is a deficient number, since it is larger than the sum of its proper divisors (51864513).

81288255 is a wasteful number, since it uses less digits than its factorization.

81288255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807.

The product of its digits is 51200, while the sum is 39.

The square root of 81288255 is about 9015.9999445430. Note that the first 4 decimals coincide. The cubic root of 81288255 is about 433.1875173423.

The spelling of 81288255 in words is "eighty-one million, two hundred eighty-eight thousand, two hundred fifty-five".