81831967 has 8 divisors (see below), whose sum is σ = 95697536. Its totient is φ = 68510232.

The previous prime is 81831929. The next prime is 81832019. The reversal of 81831967 is 76913818.

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

It is not a de Polignac number, because 81831967 - 2¹⁹ = 81307679 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81831067) 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, 135633 + ... + 136234.

It is an arithmetic number, because the mean of its divisors is an integer number (11962192).

Almost surely, 2^81831967 is an apocalyptic number.

81831967 is a deficient number, since it is larger than the sum of its proper divisors (13865569).

81831967 is a wasteful number, since it uses less digits than its factorization.

81831967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271917.

The product of its digits is 72576, while the sum is 43.

The square root of 81831967 is about 9046.1023098349. The cubic root of 81831967 is about 434.1511910681.

The spelling of 81831967 in words is "eighty-one million, eight hundred thirty-one thousand, nine hundred sixty-seven".