71721236321 has 8 divisors (see below), whose sum is σ = 81975930624. Its totient is φ = 61468742880.

The previous prime is 71721236273. The next prime is 71721236359. The reversal of 71721236321 is 12363212717.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71721236321 - 2³⁴ = 54541367137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71721236381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 479780 + ... + 611253.

It is an arithmetic number, because the mean of its divisors is an integer number (10246991328).

Almost surely, 2^71721236321 is an apocalyptic number.

It is an amenable number.

71721236321 is a deficient number, since it is larger than the sum of its proper divisors (10254694303).

71721236321 is a wasteful number, since it uses less digits than its factorization.

71721236321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1100431.

The product of its digits is 21168, while the sum is 35.

The spelling of 71721236321 in words is "seventy-one billion, seven hundred twenty-one million, two hundred thirty-six thousand, three hundred twenty-one".