9991379 has 2 divisors, whose sum is σ = 9991380. Its totient is φ = 9991378.

The previous prime is 9991357. The next prime is 9991409. The reversal of 9991379 is 9731999.

It is a happy number.

9991379 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9991379 - 2⁸ = 9991123 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9991349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995689 + 4995690.

It is an arithmetic number, because the mean of its divisors is an integer number (4995690).

Almost surely, 2^9991379 is an apocalyptic number.

9991379 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991379 is an equidigital number, since it uses as much as digits as its factorization.

9991379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 137781, while the sum is 47.

The square root of 9991379 is about 3160.9142664742. The cubic root of 9991379 is about 215.3815399319.

The spelling of 9991379 in words is "nine million, nine hundred ninety-one thousand, three hundred seventy-nine".