11783821 has 4 divisors (see below), whose sum is σ = 13467232. Its totient is φ = 10100412.

The previous prime is 11783809. The next prime is 11783833. The reversal of 11783821 is 12838711.

It is a happy number.

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: 12838711 = 1049 ⋅12239.

It is an interprime number because it is at equal distance from previous prime (11783809) and next prime (11783833).

It is not a de Polignac number, because 11783821 - 2⁷ = 11783693 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 (11783801) 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, 841695 + ... + 841708.

It is an arithmetic number, because the mean of its divisors is an integer number (3366808).

Almost surely, 2^11783821 is an apocalyptic number.

It is an amenable number.

11783821 is a deficient number, since it is larger than the sum of its proper divisors (1683411).

11783821 is an equidigital number, since it uses as much as digits as its factorization.

11783821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1683410.

The product of its digits is 2688, while the sum is 31.

The square root of 11783821 is about 3432.7570551963. The cubic root of 11783821 is about 227.5597138263.

It can be divided in two parts, 117 and 83821, that added together give a palindrome (83938).

The spelling of 11783821 in words is "eleven million, seven hundred eighty-three thousand, eight hundred twenty-one".