81258585 has 16 divisors (see below), whose sum is σ = 130325760. Its totient is φ = 43233920.

The previous prime is 81258557. The next prime is 81258607. The reversal of 81258585 is 58585218.

It is not a de Polignac number, because 81258585 - 2¹¹ = 81256537 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181 + ... + 12749.

It is an arithmetic number, because the mean of its divisors is an integer number (8145360).

Almost surely, 2^81258585 is an apocalyptic number.

It is an amenable number.

81258585 is a deficient number, since it is larger than the sum of its proper divisors (49067175).

81258585 is a wasteful number, since it uses less digits than its factorization.

81258585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13008.

The product of its digits is 128000, while the sum is 42.

The square root of 81258585 is about 9014.3543861998. The cubic root of 81258585 is about 433.1348068260.

The spelling of 81258585 in words is "eighty-one million, two hundred fifty-eight thousand, five hundred eighty-five".