71987243 has 2 divisors, whose sum is σ = 71987244. Its totient is φ = 71987242.

The previous prime is 71987233. The next prime is 71987273. The reversal of 71987243 is 34278917.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71987243 - 2¹⁰ = 71986219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71987243.

It is not a weakly prime, because it can be changed into another prime (71987233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35993621 + 35993622.

It is an arithmetic number, because the mean of its divisors is an integer number (35993622).

Almost surely, 2^71987243 is an apocalyptic number.

71987243 is a deficient number, since it is larger than the sum of its proper divisors (1).

71987243 is an equidigital number, since it uses as much as digits as its factorization.

71987243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 41.

The square root of 71987243 is about 8484.5296275044. The cubic root of 71987243 is about 415.9921931320.

It can be divided in two parts, 7198 and 7243, that added together give a palindrome (14441).

The spelling of 71987243 in words is "seventy-one million, nine hundred eighty-seven thousand, two hundred forty-three".