10991969 has 4 divisors (see below), whose sum is σ = 11016900. Its totient is φ = 10967040.

The previous prime is 10991951. The next prime is 10991983. The reversal of 10991969 is 96919901.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2512225 + 8479744 = 1585^2 + 2912^2 .

It is a cyclic number.

It is not a de Polignac number, because 10991969 - 2⁸ = 10991713 is a prime.

It is a super-2 number, since 2×10991969² = 241646764993922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10991909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11792 + ... + 12689.

It is an arithmetic number, because the mean of its divisors is an integer number (2754225).

Almost surely, 2^10991969 is an apocalyptic number.

It is an amenable number.

10991969 is a deficient number, since it is larger than the sum of its proper divisors (24931).

10991969 is an equidigital number, since it uses as much as digits as its factorization.

10991969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24930.

The product of its (nonzero) digits is 39366, while the sum is 44.

The square root of 10991969 is about 3315.4138504868. The cubic root of 10991969 is about 222.3438722917.

The spelling of 10991969 in words is "ten million, nine hundred ninety-one thousand, nine hundred sixty-nine".