11992991 has 4 divisors (see below), whose sum is σ = 12087552. Its totient is φ = 11898432.

The previous prime is 11992987. The next prime is 11992993. The reversal of 11992991 is 19929911.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19929911 = 97 ⋅205463.

It is a cyclic number.

It is not a de Polignac number, because 11992991 - 2² = 11992987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11992993) 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 3 ways as a sum of consecutive naturals, for example, 47090 + ... + 47343.

It is an arithmetic number, because the mean of its divisors is an integer number (3021888).

Almost surely, 2^11992991 is an apocalyptic number.

11992991 is a deficient number, since it is larger than the sum of its proper divisors (94561).

11992991 is an equidigital number, since it uses as much as digits as its factorization.

11992991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94560.

The product of its digits is 13122, while the sum is 41.

The square root of 11992991 is about 3463.0898053617. The cubic root of 11992991 is about 228.8982659289.

It can be divided in two parts, 11 and 992991, that multiplied together give a palindrome (10922901).

The spelling of 11992991 in words is "eleven million, nine hundred ninety-two thousand, nine hundred ninety-one".