81838087 has 4 divisors (see below), whose sum is σ = 84660120. Its totient is φ = 79016056.

The previous prime is 81838069. The next prime is 81838093. The reversal of 81838087 is 78083818.

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

It is a cyclic number.

It is not a de Polignac number, because 81838087 - 2¹¹ = 81836039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81838007) 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, 1410973 + ... + 1411030.

It is an arithmetic number, because the mean of its divisors is an integer number (21165030).

Almost surely, 2^81838087 is an apocalyptic number.

81838087 is a deficient number, since it is larger than the sum of its proper divisors (2822033).

81838087 is a wasteful number, since it uses less digits than its factorization.

81838087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2822032.

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 81838087 is about 9046.4405707438. The cubic root of 81838087 is about 434.1620138111.

The spelling of 81838087 in words is "eighty-one million, eight hundred thirty-eight thousand, eighty-seven".