71218465639 has 4 divisors (see below), whose sum is σ = 71224336024. Its totient is φ = 71212595256.

The previous prime is 71218465613. The next prime is 71218465673. The reversal of 71218465639 is 93656481217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93656481217 = 13 ⋅7204344709.

It is a cyclic number.

It is not a de Polignac number, because 71218465639 - 2⁷ = 71218465511 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 (71218465609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2916957 + ... + 2941270.

It is an arithmetic number, because the mean of its divisors is an integer number (17806084006).

Almost surely, 2^71218465639 is an apocalyptic number.

71218465639 is a deficient number, since it is larger than the sum of its proper divisors (5870385).

71218465639 is a wasteful number, since it uses less digits than its factorization.

71218465639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5870384.

The product of its digits is 2177280, while the sum is 52.

The spelling of 71218465639 in words is "seventy-one billion, two hundred eighteen million, four hundred sixty-five thousand, six hundred thirty-nine".