11998491 has 4 divisors (see below), whose sum is σ = 15997992. Its totient is φ = 7998992.

The previous prime is 11998487. The next prime is 11998501. The reversal of 11998491 is 19489911.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 11998491 - 2² = 11998487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11998391) 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, 1999746 + ... + 1999751.

It is an arithmetic number, because the mean of its divisors is an integer number (3999498).

Almost surely, 2^11998491 is an apocalyptic number.

11998491 is a deficient number, since it is larger than the sum of its proper divisors (3999501).

11998491 is an equidigital number, since it uses as much as digits as its factorization.

11998491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3999500.

The product of its digits is 23328, while the sum is 42.

The square root of 11998491 is about 3463.8838029010. The cubic root of 11998491 is about 228.9332515873.

The spelling of 11998491 in words is "eleven million, nine hundred ninety-eight thousand, four hundred ninety-one".