81382806 has 40 divisors (see below), whose sum is σ = 184273320. Its totient is φ = 26842752.

The previous prime is 81382753. The next prime is 81382811. The reversal of 81382806 is 60828318.

It is a super-2 number, since 2×81382806² = 13246322224867272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13125 + ... + 18303.

It is an arithmetic number, because the mean of its divisors is an integer number (4606833).

Almost surely, 2^81382806 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81382806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92136660).

81382806 is an abundant number, since it is smaller than the sum of its proper divisors (102890514).

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

81382806 is a wasteful number, since it uses less digits than its factorization.

81382806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5290 (or 5281 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 81382806 is about 9021.2419322397. The cubic root of 81382806 is about 433.3554072911.

The spelling of 81382806 in words is "eighty-one million, three hundred eighty-two thousand, eight hundred six".