71067991 has 4 divisors (see below), whose sum is σ = 71321184. Its totient is φ = 70814800.

The previous prime is 71067979. The next prime is 71068001. The reversal of 71067991 is 19976017.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19976017 = 3797 ⋅5261.

It is a cyclic number.

It is not a de Polignac number, because 71067991 - 2¹⁷ = 70936919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71067091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126175 + ... + 126736.

It is an arithmetic number, because the mean of its divisors is an integer number (17830296).

Almost surely, 2^71067991 is an apocalyptic number.

71067991 is a deficient number, since it is larger than the sum of its proper divisors (253193).

71067991 is a wasteful number, since it uses less digits than its factorization.

71067991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253192.

The product of its (nonzero) digits is 23814, while the sum is 40.

The square root of 71067991 is about 8430.1833313398. The cubic root of 71067991 is about 414.2139103970.

The spelling of 71067991 in words is "seventy-one million, sixty-seven thousand, nine hundred ninety-one".