11922821 has 2 divisors, whose sum is σ = 11922822. Its totient is φ = 11922820.

The previous prime is 11922811. The next prime is 11922829. The reversal of 11922821 is 12822911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11826721 + 96100 = 3439^2 + 310^2 .

It is an emirp because it is prime and its reverse (12822911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11922821 - 2¹⁴ = 11906437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11922829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5961410 + 5961411.

It is an arithmetic number, because the mean of its divisors is an integer number (5961411).

Almost surely, 2^11922821 is an apocalyptic number.

It is an amenable number.

11922821 is a deficient number, since it is larger than the sum of its proper divisors (1).

11922821 is an equidigital number, since it uses as much as digits as its factorization.

11922821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 26.

The square root of 11922821 is about 3452.9438165137. The cubic root of 11922821 is about 228.4509708116.

The spelling of 11922821 in words is "eleven million, nine hundred twenty-two thousand, eight hundred twenty-one".