81831590 has 8 divisors (see below), whose sum is σ = 147296880. Its totient is φ = 32732632.

The previous prime is 81831587. The next prime is 81831593. The reversal of 81831590 is 9513818.

It is an interprime number because it is at equal distance from previous prime (81831587) and next prime (81831593).

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

It is a self number, because there is not a number n which added to its sum of digits gives 81831590.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81831593) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4091570 + ... + 4091589.

It is an arithmetic number, because the mean of its divisors is an integer number (18412110).

Almost surely, 2^81831590 is an apocalyptic number.

81831590 is a deficient number, since it is larger than the sum of its proper divisors (65465290).

81831590 is a wasteful number, since it uses less digits than its factorization.

81831590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8183166.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 81831590 is about 9046.0814721071. The cubic root of 81831590 is about 434.1505243553.

The spelling of 81831590 in words is "eighty-one million, eight hundred thirty-one thousand, five hundred ninety".