71218643 has 4 divisors (see below), whose sum is σ = 71294328. Its totient is φ = 71142960.

The previous prime is 71218597. The next prime is 71218657. The reversal of 71218643 is 34681217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34681217 = 23 ⋅1507879.

It is a cyclic number.

It is not a de Polignac number, because 71218643 - 2¹⁸ = 70956499 is a prime.

It is a super-2 number, since 2×71218643² = 10144190221522898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71218663) 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, 36413 + ... + 38318.

It is an arithmetic number, because the mean of its divisors is an integer number (17823582).

Almost surely, 2^71218643 is an apocalyptic number.

71218643 is a deficient number, since it is larger than the sum of its proper divisors (75685).

71218643 is an equidigital number, since it uses as much as digits as its factorization.

71218643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75684.

The product of its digits is 8064, while the sum is 32.

The square root of 71218643 is about 8439.1138752834. The cubic root of 71218643 is about 414.5063914002.

The spelling of 71218643 in words is "seventy-one million, two hundred eighteen thousand, six hundred forty-three".