81382805 has 16 divisors (see below), whose sum is σ = 111849984. Its totient is φ = 55685760.

The previous prime is 81382753. The next prime is 81382811. The reversal of 81382805 is 50828318.

It is not a de Polignac number, because 81382805 - 2¹⁴ = 81366421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16004 + ... + 20466.

It is an arithmetic number, because the mean of its divisors is an integer number (6990624).

Almost surely, 2^81382805 is an apocalyptic number.

It is an amenable number.

81382805 is a deficient number, since it is larger than the sum of its proper divisors (30467179).

81382805 is a wasteful number, since it uses less digits than its factorization.

81382805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4996.

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 81382805 is about 9021.2418768150. The cubic root of 81382805 is about 433.3554055161.

The spelling of 81382805 in words is "eighty-one million, three hundred eighty-two thousand, eight hundred five".