73721849581 has 2 divisors, whose sum is σ = 73721849582. Its totient is φ = 73721849580.

The previous prime is 73721849527. The next prime is 73721849587. The reversal of 73721849581 is 18594812737.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53503853481 + 20217996100 = 231309^2 + 142190^2 .

It is a cyclic number.

It is not a de Polignac number, because 73721849581 - 2¹¹ = 73721847533 is a prime.

It is a super-2 number, since 2×73721849581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73721849587) 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, 36860924790 + 36860924791.

It is an arithmetic number, because the mean of its divisors is an integer number (36860924791).

Almost surely, 2^73721849581 is an apocalyptic number.

It is an amenable number.

73721849581 is a deficient number, since it is larger than the sum of its proper divisors (1).

73721849581 is an equidigital number, since it uses as much as digits as its factorization.

73721849581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3386880, while the sum is 55.

The spelling of 73721849581 in words is "seventy-three billion, seven hundred twenty-one million, eight hundred forty-nine thousand, five hundred eighty-one".