81057385 has 8 divisors (see below), whose sum is σ = 98441280. Its totient is φ = 64064304.

The previous prime is 81057367. The next prime is 81057391. The reversal of 81057385 is 58375018.

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

It is a cyclic number.

It is not a de Polignac number, because 81057385 - 2⁷ = 81057257 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97245 + ... + 98074.

It is an arithmetic number, because the mean of its divisors is an integer number (12305160).

Almost surely, 2^81057385 is an apocalyptic number.

It is an amenable number.

81057385 is a deficient number, since it is larger than the sum of its proper divisors (17383895).

81057385 is a wasteful number, since it uses less digits than its factorization.

81057385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195407.

The product of its (nonzero) digits is 33600, while the sum is 37.

The square root of 81057385 is about 9003.1874911056. The cubic root of 81057385 is about 432.7770241225. Note that the first 3 decimals are identical.

The spelling of 81057385 in words is "eighty-one million, fifty-seven thousand, three hundred eighty-five".