9979119781 has 2 divisors, whose sum is σ = 9979119782. Its totient is φ = 9979119780.

The previous prime is 9979119767. The next prime is 9979119803. The reversal of 9979119781 is 1879119799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9416955681 + 562164100 = 97041^2 + 23710^2 .

It is a cyclic number.

It is not a de Polignac number, because 9979119781 - 2⁷ = 9979119653 is a prime.

It is a super-2 number, since 2×9979119781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9979119581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989559890 + 4989559891.

It is an arithmetic number, because the mean of its divisors is an integer number (4989559891).

Almost surely, 2^9979119781 is an apocalyptic number.

It is an amenable number.

9979119781 is a deficient number, since it is larger than the sum of its proper divisors (1).

9979119781 is an equidigital number, since it uses as much as digits as its factorization.

9979119781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2571912, while the sum is 61.

The square root of 9979119781 is about 99895.5443500860. The cubic root of 9979119781 is about 2152.9341428834.

The spelling of 9979119781 in words is "nine billion, nine hundred seventy-nine million, one hundred nineteen thousand, seven hundred eighty-one".