81025085 has 8 divisors (see below), whose sum is σ = 97373016. Its totient is φ = 64724800.

The previous prime is 81025037. The next prime is 81025093. The reversal of 81025085 is 58052018.

It can be written as a sum of positive squares in 4 ways, for example, as 1708249 + 79316836 = 1307^2 + 8906^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81025085 - 2¹⁰ = 81024061 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 8054 + ... + 15063.

It is an arithmetic number, because the mean of its divisors is an integer number (12171627).

Almost surely, 2^81025085 is an apocalyptic number.

It is an amenable number.

81025085 is a deficient number, since it is larger than the sum of its proper divisors (16347931).

81025085 is a wasteful number, since it uses less digits than its factorization.

81025085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23823.

The product of its (nonzero) digits is 3200, while the sum is 29.

The square root of 81025085 is about 9001.3935032305. The cubic root of 81025085 is about 432.7195317050.

The spelling of 81025085 in words is "eighty-one million, twenty-five thousand, eighty-five".