11991497 has 4 divisors (see below), whose sum is σ = 13704576. Its totient is φ = 10278420.

The previous prime is 11991481. The next prime is 11991517. The reversal of 11991497 is 79419911.

11991497 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79419911 = 41 ⋅1937071.

It is a cyclic number.

It is not a de Polignac number, because 11991497 - 2⁴ = 11991481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11991407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 856529 + ... + 856542.

It is an arithmetic number, because the mean of its divisors is an integer number (3426144).

Almost surely, 2^11991497 is an apocalyptic number.

It is an amenable number.

11991497 is a deficient number, since it is larger than the sum of its proper divisors (1713079).

11991497 is an equidigital number, since it uses as much as digits as its factorization.

11991497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1713078.

The product of its digits is 20412, while the sum is 41.

The square root of 11991497 is about 3462.8740953145. The cubic root of 11991497 is about 228.8887607045. Note that the first 3 decimals are identical.

The spelling of 11991497 in words is "eleven million, nine hundred ninety-one thousand, four hundred ninety-seven".