71816639 has 2 divisors, whose sum is σ = 71816640. Its totient is φ = 71816638.

The previous prime is 71816623. The next prime is 71816669. The reversal of 71816639 is 93661817.

It is a weak prime.

It is an emirp because it is prime and its reverse (93661817) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71816639 - 2⁴ = 71816623 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 71816596 and 71816605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71816669) 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 as a sum of consecutive naturals, namely, 35908319 + 35908320.

It is an arithmetic number, because the mean of its divisors is an integer number (35908320).

Almost surely, 2^71816639 is an apocalyptic number.

71816639 is a deficient number, since it is larger than the sum of its proper divisors (1).

71816639 is an equidigital number, since it uses as much as digits as its factorization.

71816639 is an odious number, because the sum of its binary digits is odd.

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

The square root of 71816639 is about 8474.4698359248. The cubic root of 71816639 is about 415.6633104604.

The spelling of 71816639 in words is "seventy-one million, eight hundred sixteen thousand, six hundred thirty-nine".