81000847 has 8 divisors (see below), whose sum is σ = 82363392. Its totient is φ = 79644600.

The previous prime is 81000841. The next prime is 81000859. The reversal of 81000847 is 74800018.

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 81000847 - 2⁷ = 81000719 is a prime.

It is a super-2 number, since 2×81000847² = 13122274429434818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81000841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29278 + ... + 31924.

It is an arithmetic number, because the mean of its divisors is an integer number (10295424).

Almost surely, 2^81000847 is an apocalyptic number.

81000847 is a deficient number, since it is larger than the sum of its proper divisors (1362545).

81000847 is a wasteful number, since it uses less digits than its factorization.

81000847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3149.

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 81000847 is about 9000.0470554325. The cubic root of 81000847 is about 432.6763792171.

The spelling of 81000847 in words is "eighty-one million, eight hundred forty-seven", and thus it is an aban number.