10000999991 has 2 divisors, whose sum is σ = 10000999992. Its totient is φ = 10000999990.

The previous prime is 10000999979. The next prime is 10000999997. The reversal of 10000999991 is 19999900001.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 10000999991 - 2¹⁴ = 10000983607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10000999997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5000499995 + 5000499996.

It is an arithmetic number, because the mean of its divisors is an integer number (5000499996).

Almost surely, 2^10000999991 is an apocalyptic number.

10000999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

10000999991 is an equidigital number, since it uses as much as digits as its factorization.

10000999991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 59049, while the sum is 47.

The spelling of 10000999991 in words is "ten billion, nine hundred ninety-nine thousand, nine hundred ninety-one".