71891086 has 4 divisors (see below), whose sum is σ = 107836632. Its totient is φ = 35945542.

The previous prime is 71891051. The next prime is 71891101. The reversal of 71891086 is 68019817.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68019817 = 1997 ⋅34061.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17972770 + ... + 17972773.

It is an arithmetic number, because the mean of its divisors is an integer number (26959158).

Almost surely, 2^71891086 is an apocalyptic number.

71891086 is a deficient number, since it is larger than the sum of its proper divisors (35945546).

71891086 is a wasteful number, since it uses less digits than its factorization.

71891086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35945545.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 71891086 is about 8478.8611263542. The cubic root of 71891086 is about 415.8068899999.

The spelling of 71891086 in words is "seventy-one million, eight hundred ninety-one thousand, eighty-six".