67850721805 has 4 divisors (see below), whose sum is σ = 81420866172. Its totient is φ = 54280577440.

The previous prime is 67850721779. The next prime is 67850721823. The reversal of 67850721805 is 50812705876.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28177651044 + 39673070761 = 167862^2 + 199181^2 .

It is not a de Polignac number, because 67850721805 - 2¹⁹ = 67850197517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6785072176 + ... + 6785072185.

It is an arithmetic number, because the mean of its divisors is an integer number (20355216543).

Almost surely, 2^67850721805 is an apocalyptic number.

It is an amenable number.

67850721805 is a deficient number, since it is larger than the sum of its proper divisors (13570144367).

67850721805 is a wasteful number, since it uses less digits than its factorization.

67850721805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13570144366.

The product of its (nonzero) digits is 940800, while the sum is 49.

The spelling of 67850721805 in words is "sixty-seven billion, eight hundred fifty million, seven hundred twenty-one thousand, eight hundred five".