71216591 has 4 divisors (see below), whose sum is σ = 71421000. Its totient is φ = 71012184.

The previous prime is 71216581. The next prime is 71216597. The reversal of 71216591 is 19561217.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71216591 is a prime.

It is a super-2 number, since 2×71216591² = 10143605667322562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71216597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101681 + ... + 102378.

It is an arithmetic number, because the mean of its divisors is an integer number (17855250).

Almost surely, 2^71216591 is an apocalyptic number.

71216591 is a deficient number, since it is larger than the sum of its proper divisors (204409).

71216591 is a wasteful number, since it uses less digits than its factorization.

71216591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204408.

The product of its digits is 3780, while the sum is 32.

The square root of 71216591 is about 8438.9922976621. The cubic root of 71216591 is about 414.5024103486.

The spelling of 71216591 in words is "seventy-one million, two hundred sixteen thousand, five hundred ninety-one".