81587867 has 8 divisors (see below), whose sum is σ = 82395552. Its totient is φ = 80784000.

The previous prime is 81587851. The next prime is 81587873. The reversal of 81587867 is 76878518.

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

It is a cyclic number.

It is not a de Polignac number, because 81587867 - 2⁴ = 81587851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81587837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59267 + ... + 60627.

It is an arithmetic number, because the mean of its divisors is an integer number (10299444).

Almost surely, 2^81587867 is an apocalyptic number.

81587867 is a deficient number, since it is larger than the sum of its proper divisors (807685).

81587867 is a wasteful number, since it uses less digits than its factorization.

81587867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1909.

The product of its digits is 752640, while the sum is 50.

The square root of 81587867 is about 9032.6002347054. The cubic root of 81587867 is about 433.7190785399.

The spelling of 81587867 in words is "eighty-one million, five hundred eighty-seven thousand, eight hundred sixty-seven".