9717980781 has 16 divisors (see below), whose sum is σ = 13391682048. Its totient is φ = 6261979200.

The previous prime is 9717980743. The next prime is 9717980807. The reversal of 9717980781 is 1870897179.

It is not a de Polignac number, because 9717980781 - 2⁶ = 9717980717 is a prime.

It is a super-2 number, since 2×9717980781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9717980281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12715 + ... + 139991.

It is an arithmetic number, because the mean of its divisors is an integer number (836980128).

Almost surely, 2^9717980781 is an apocalyptic number.

It is an amenable number.

9717980781 is a deficient number, since it is larger than the sum of its proper divisors (3673701267).

9717980781 is a wasteful number, since it uses less digits than its factorization.

9717980781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128132.

The product of its (nonzero) digits is 1778112, while the sum is 57.

The square root of 9717980781 is about 98579.8193394571. The cubic root of 9717980781 is about 2133.9881916666.

The spelling of 9717980781 in words is "nine billion, seven hundred seventeen million, nine hundred eighty thousand, seven hundred eighty-one".