81286758 has 96 divisors (see below), whose sum is σ = 215452224. Its totient is φ = 21620736.

The previous prime is 81286729. The next prime is 81286763. The reversal of 81286758 is 85768218.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 293316 + ... + 293592.

It is an arithmetic number, because the mean of its divisors is an integer number (2244294).

Almost surely, 2^81286758 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81286758, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107726112).

81286758 is an abundant number, since it is smaller than the sum of its proper divisors (134165466).

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

81286758 is a wasteful number, since it uses less digits than its factorization.

81286758 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446 (or 443 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The square root of 81286758 is about 9015.9169250831. The cubic root of 81286758 is about 433.1848581402.

The spelling of 81286758 in words is "eighty-one million, two hundred eighty-six thousand, seven hundred fifty-eight".