81039085 has 32 divisors (see below), whose sum is σ = 109468800. Its totient is φ = 57390336.

The previous prime is 81039043. The next prime is 81039107. The reversal of 81039085 is 58093018.

It is not a de Polignac number, because 81039085 - 2⁷ = 81038957 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81039085.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 582946 + ... + 583084.

It is an arithmetic number, because the mean of its divisors is an integer number (3420900).

Almost surely, 2^81039085 is an apocalyptic number.

81039085 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81039085 is a deficient number, since it is larger than the sum of its proper divisors (28429715).

81039085 is a wasteful number, since it uses less digits than its factorization.

81039085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 81039085 is about 9002.1711270115. The cubic root of 81039085 is about 432.7444528948.

The spelling of 81039085 in words is "eighty-one million, thirty-nine thousand, eighty-five".