11521421 has 2 divisors, whose sum is σ = 11521422. Its totient is φ = 11521420.

The previous prime is 11521379. The next prime is 11521453. The reversal of 11521421 is 12412511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11485321 + 36100 = 3389^2 + 190^2 .

It is an emirp because it is prime and its reverse (12412511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11521421 - 2¹⁸ = 11259277 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11521421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11521021) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5760710 + 5760711.

It is an arithmetic number, because the mean of its divisors is an integer number (5760711).

Almost surely, 2^11521421 is an apocalyptic number.

It is an amenable number.

11521421 is a deficient number, since it is larger than the sum of its proper divisors (1).

11521421 is an equidigital number, since it uses as much as digits as its factorization.

11521421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 80, while the sum is 17.

The square root of 11521421 is about 3394.3218763105. The cubic root of 11521421 is about 225.8579327455.

Adding to 11521421 its reverse (12412511), we get a palindrome (23933932).

The spelling of 11521421 in words is "eleven million, five hundred twenty-one thousand, four hundred twenty-one".