71686081 has 4 divisors (see below), whose sum is σ = 73434564. Its totient is φ = 69937600.

The previous prime is 71686067. The next prime is 71686103. The reversal of 71686081 is 18068617.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1461681 + 70224400 = 1209^2 + 8380^2 .

It is a cyclic number.

It is not a de Polignac number, because 71686081 - 2⁵ = 71686049 is a prime.

It is a super-2 number, since 2×71686081² = 10277788418277122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71686081.

It is not an unprimeable number, because it can be changed into a prime (71686061) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 874180 + ... + 874261.

It is an arithmetic number, because the mean of its divisors is an integer number (18358641).

Almost surely, 2^71686081 is an apocalyptic number.

It is an amenable number.

71686081 is a deficient number, since it is larger than the sum of its proper divisors (1748483).

71686081 is a wasteful number, since it uses less digits than its factorization.

71686081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1748482.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 71686081 is about 8466.7633130967. The cubic root of 71686081 is about 415.4112746748.

The spelling of 71686081 in words is "seventy-one million, six hundred eighty-six thousand, eighty-one".