71530038721 has 4 divisors (see below), whose sum is σ = 71530639492. Its totient is φ = 71529437952.

The previous prime is 71530038641. The next prime is 71530038803. The reversal of 71530038721 is 12783003517.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 337126321 + 71192912400 = 18361^2 + 266820^2 .

It is a cyclic number.

It is not a de Polignac number, because 71530038721 - 2¹⁷ = 71529907649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71530038121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54936 + ... + 382201.

It is an arithmetic number, because the mean of its divisors is an integer number (17882659873).

Almost surely, 2^71530038721 is an apocalyptic number.

It is an amenable number.

71530038721 is a deficient number, since it is larger than the sum of its proper divisors (600771).

71530038721 is a wasteful number, since it uses less digits than its factorization.

71530038721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600770.

The product of its (nonzero) digits is 35280, while the sum is 37.

The spelling of 71530038721 in words is "seventy-one billion, five hundred thirty million, thirty-eight thousand, seven hundred twenty-one".