9979681 has 2 divisors, whose sum is σ = 9979682. Its totient is φ = 9979680.

The previous prime is 9979643. The next prime is 9979727. The reversal of 9979681 is 1869799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9979281 + 400 = 3159^2 + 20^2 .

It is a cyclic number.

It is not a de Polignac number, because 9979681 - 2⁷ = 9979553 is a prime.

It is a super-2 number, since 2×9979681² = 199188065723522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (9979621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989840 + 4989841.

It is an arithmetic number, because the mean of its divisors is an integer number (4989841).

Almost surely, 2^9979681 is an apocalyptic number.

It is an amenable number.

9979681 is a deficient number, since it is larger than the sum of its proper divisors (1).

9979681 is an equidigital number, since it uses as much as digits as its factorization.

9979681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 49.

The square root of 9979681 is about 3159.0633105400. The cubic root of 9979681 is about 215.2974501984.

The spelling of 9979681 in words is "nine million, nine hundred seventy-nine thousand, six hundred eighty-one".