99991011 has 16 divisors (see below), whose sum is σ = 135820800. Its totient is φ = 65421408.

The previous prime is 99991009. The next prime is 99991033. The reversal of 99991011 is 11019999.

99991011 is a nontrivial binomial coefficient, being equal to C(14142, 2).

It is not a de Polignac number, because 99991011 - 2¹ = 99991009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (99991081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41245 + ... + 43601.

It is an arithmetic number, because the mean of its divisors is an integer number (8488800).

Almost surely, 2^99991011 is an apocalyptic number.

99991011 is the 14141-st triangular number and also the 7071-st hexagonal number.

99991011 is a deficient number, since it is larger than the sum of its proper divisors (35829789).

99991011 is a wasteful number, since it uses less digits than its factorization.

99991011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2618.

The product of its (nonzero) digits is 6561, while the sum is 39.

The square root of 99991011 is about 9999.5505398993. The cubic root of 99991011 is about 464.1449751972.

The spelling of 99991011 in words is "ninety-nine million, nine hundred ninety-one thousand, eleven".