81058575 has 24 divisors (see below), whose sum is σ = 144327568. Its totient is φ = 39905280.

The previous prime is 81058573. The next prime is 81058633. The reversal of 81058575 is 57585018.

It is not a de Polignac number, because 81058575 - 2¹ = 81058573 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81058573) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40594 + ... + 42543.

Almost surely, 2^81058575 is an apocalyptic number.

81058575 is a deficient number, since it is larger than the sum of its proper divisors (63268993).

81058575 is a wasteful number, since it uses less digits than its factorization.

81058575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83163 (or 83158 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 39.

The square root of 81058575 is about 9003.2535785681. The cubic root of 81058575 is about 432.7791419724.

The spelling of 81058575 in words is "eighty-one million, fifty-eight thousand, five hundred seventy-five".