9720971807 has 4 divisors (see below), whose sum is σ = 10292793696. Its totient is φ = 9149149920.

The previous prime is 9720971803. The next prime is 9720971809. The reversal of 9720971807 is 7081790279.

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

It is a cyclic number.

It is not a de Polignac number, because 9720971807 - 2² = 9720971803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9720971803) 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, 285910919 + ... + 285910952.

It is an arithmetic number, because the mean of its divisors is an integer number (2573198424).

Almost surely, 2^9720971807 is an apocalyptic number.

9720971807 is a deficient number, since it is larger than the sum of its proper divisors (571821889).

9720971807 is a wasteful number, since it uses less digits than its factorization.

9720971807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571821888.

The product of its (nonzero) digits is 444528, while the sum is 50.

The square root of 9720971807 is about 98594.9887519645. The cubic root of 9720971807 is about 2134.2071040648.

The spelling of 9720971807 in words is "nine billion, seven hundred twenty million, nine hundred seventy-one thousand, eight hundred seven".