81255015 has 16 divisors (see below), whose sum is σ = 144453600. Its totient is φ = 43335936.

The previous prime is 81255007. The next prime is 81255017. The reversal of 81255015 is 51055218.

It is not a de Polignac number, because 81255015 - 2³ = 81255007 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 81255015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81255017) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 300810 + ... + 301079.

It is an arithmetic number, because the mean of its divisors is an integer number (9028350).

Almost surely, 2^81255015 is an apocalyptic number.

81255015 is a deficient number, since it is larger than the sum of its proper divisors (63198585).

81255015 is a wasteful number, since it uses less digits than its factorization.

81255015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601903 (or 601897 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 81255015 is about 9014.1563665159. The cubic root of 81255015 is about 433.1284636443.

The spelling of 81255015 in words is "eighty-one million, two hundred fifty-five thousand, fifteen".