9979639 has 2 divisors, whose sum is σ = 9979640. Its totient is φ = 9979638.

The previous prime is 9979621. The next prime is 9979643. The reversal of 9979639 is 9369799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9979639 - 2⁷ = 9979511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9979609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989819 + 4989820.

It is an arithmetic number, because the mean of its divisors is an integer number (4989820).

Almost surely, 2^9979639 is an apocalyptic number.

9979639 is a deficient number, since it is larger than the sum of its proper divisors (1).

9979639 is an equidigital number, since it uses as much as digits as its factorization.

9979639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 826686, while the sum is 52.

The square root of 9979639 is about 3159.0566629929. The cubic root of 9979639 is about 215.2971481678.

The spelling of 9979639 in words is "nine million, nine hundred seventy-nine thousand, six hundred thirty-nine".