81389847 has 32 divisors (see below), whose sum is σ = 141189120. Its totient is φ = 40439520.

The previous prime is 81389827. The next prime is 81389857. The reversal of 81389847 is 74898318.

It is not a de Polignac number, because 81389847 - 2¹⁴ = 81373463 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81389796 and 81389805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81389807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2347 + ... + 12972.

It is an arithmetic number, because the mean of its divisors is an integer number (4412160).

Almost surely, 2^81389847 is an apocalyptic number.

81389847 is a deficient number, since it is larger than the sum of its proper divisors (59799273).

81389847 is a wasteful number, since it uses less digits than its factorization.

81389847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15363.

The product of its digits is 387072, while the sum is 48.

The square root of 81389847 is about 9021.6321694026. The cubic root of 81389847 is about 433.3679044739.

The spelling of 81389847 in words is "eighty-one million, three hundred eighty-nine thousand, eight hundred forty-seven".