71891663 has 8 divisors (see below), whose sum is σ = 72546432. Its totient is φ = 71239896.

The previous prime is 71891587. The next prime is 71891683. The reversal of 71891663 is 36619817.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71891663 - 2²⁴ = 55114447 is a prime.

It is a super-2 number, since 2×71891663² = 10336822417811138, 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 71891663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71891683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90956 + ... + 91742.

It is an arithmetic number, because the mean of its divisors is an integer number (9068304).

Almost surely, 2^71891663 is an apocalyptic number.

71891663 is a deficient number, since it is larger than the sum of its proper divisors (654769).

71891663 is a wasteful number, since it uses less digits than its factorization.

71891663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1501.

The product of its digits is 54432, while the sum is 41.

The square root of 71891663 is about 8478.8951520820. The cubic root of 71891663 is about 415.8080024230.

The spelling of 71891663 in words is "seventy-one million, eight hundred ninety-one thousand, six hundred sixty-three".