81842583 has 4 divisors (see below), whose sum is σ = 109123448. Its totient is φ = 54561720.

The previous prime is 81842569. The next prime is 81842587. The reversal of 81842583 is 38524818.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81842583 - 2¹⁸ = 81580439 is a prime.

It is a super-2 number, since 2×81842583² = 13396416784223778, 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 (81842587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13640428 + ... + 13640433.

It is an arithmetic number, because the mean of its divisors is an integer number (27280862).

Almost surely, 2^81842583 is an apocalyptic number.

81842583 is a deficient number, since it is larger than the sum of its proper divisors (27280865).

81842583 is a wasteful number, since it uses less digits than its factorization.

81842583 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27280864.

The product of its digits is 61440, while the sum is 39.

The square root of 81842583 is about 9046.6890628561. The cubic root of 81842583 is about 434.1699642930.

The spelling of 81842583 in words is "eighty-one million, eight hundred forty-two thousand, five hundred eighty-three".