11993821 has 4 divisors (see below), whose sum is σ = 13707232. Its totient is φ = 10280412.

The previous prime is 11993801. The next prime is 11993843. The reversal of 11993821 is 12839911.

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.

It is a cyclic number.

It is not a de Polignac number, because 11993821 - 2¹¹ = 11991773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11993801) 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, 856695 + ... + 856708.

It is an arithmetic number, because the mean of its divisors is an integer number (3426808).

Almost surely, 2^11993821 is an apocalyptic number.

It is an amenable number.

11993821 is a deficient number, since it is larger than the sum of its proper divisors (1713411).

11993821 is an equidigital number, since it uses as much as digits as its factorization.

11993821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1713410.

The product of its digits is 3888, while the sum is 34.

The square root of 11993821 is about 3463.2096384712. The cubic root of 11993821 is about 228.9035462680.

The spelling of 11993821 in words is "eleven million, nine hundred ninety-three thousand, eight hundred twenty-one".