9991259 has 2 divisors, whose sum is σ = 9991260. Its totient is φ = 9991258.

The previous prime is 9991211. The next prime is 9991277. The reversal of 9991259 is 9521999.

9991259 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9991259 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (9991159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995629 + 4995630.

It is an arithmetic number, because the mean of its divisors is an integer number (4995630).

Almost surely, 2^9991259 is an apocalyptic number.

9991259 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991259 is an equidigital number, since it uses as much as digits as its factorization.

9991259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65610, while the sum is 44.

The square root of 9991259 is about 3160.8952845673. The cubic root of 9991259 is about 215.3806776589.

The spelling of 9991259 in words is "nine million, nine hundred ninety-one thousand, two hundred fifty-nine".