81854857 has 8 divisors (see below), whose sum is σ = 93617216. Its totient is φ = 70109712.

The previous prime is 81854837. The next prime is 81854867. The reversal of 81854857 is 75845818.

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 81854857 - 2¹¹ = 81852809 is a prime.

It is a super-2 number, since 2×81854857² = 13400435228980898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81854807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8398 + ... + 15304.

It is an arithmetic number, because the mean of its divisors is an integer number (11702152).

Almost surely, 2^81854857 is an apocalyptic number.

81854857 is the 5224-th hex number.

It is an amenable number.

81854857 is a deficient number, since it is larger than the sum of its proper divisors (11762359).

81854857 is a wasteful number, since it uses less digits than its factorization.

81854857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8607.

The product of its digits is 358400, while the sum is 46.

The square root of 81854857 is about 9047.3674071522. The cubic root of 81854857 is about 434.1916674845.

The spelling of 81854857 in words is "eighty-one million, eight hundred fifty-four thousand, eight hundred fifty-seven".