991909011 has 8 divisors (see below), whose sum is σ = 1368150480. Its totient is φ = 638470112.

The previous prime is 991908991. The next prime is 991909021. The reversal of 991909011 is 110909199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 991909011 - 2⁶ = 991908947 is a prime.

It is a super-2 number, since 2×991909011² = 1967766972205996242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991909021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5700540 + ... + 5700713.

It is an arithmetic number, because the mean of its divisors is an integer number (171018810).

Almost surely, 2^991909011 is an apocalyptic number.

991909011 is a deficient number, since it is larger than the sum of its proper divisors (376241469).

991909011 is a wasteful number, since it uses less digits than its factorization.

991909011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11401285.

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

The square root of 991909011 is about 31494.5870111040. The cubic root of 991909011 is about 997.2956970044.

The spelling of 991909011 in words is "nine hundred ninety-one million, nine hundred nine thousand, eleven".