81587850 has 48 divisors (see below), whose sum is σ = 203611968. Its totient is φ = 21619840.

The previous prime is 81587839. The next prime is 81587851. The reversal of 81587850 is 5878518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81587851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23422 + ... + 26678.

It is an arithmetic number, because the mean of its divisors is an integer number (4241916).

Almost surely, 2^81587850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81587850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101805984).

81587850 is an abundant number, since it is smaller than the sum of its proper divisors (122024118).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81587850 is a wasteful number, since it uses less digits than its factorization.

81587850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3439 (or 3434 counting only the distinct ones).

The product of its (nonzero) digits is 89600, while the sum is 42.

The square root of 81587850 is about 9032.5992936696. The cubic root of 81587850 is about 433.7190484161.

The spelling of 81587850 in words is "eighty-one million, five hundred eighty-seven thousand, eight hundred fifty".