11261821 has 2 divisors, whose sum is σ = 11261822. Its totient is φ = 11261820.

The previous prime is 11261819. The next prime is 11261843. The reversal of 11261821 is 12816211.

It is an a-pointer prime, because the next prime (11261843) can be obtained adding 11261821 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10791225 + 470596 = 3285^2 + 686^2 .

It is an emirp because it is prime and its reverse (12816211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11261821 - 2¹ = 11261819 is a prime.

It is a super-2 number, since 2×11261821² = 253657224472082, which contains 22 as substring.

Together with 11261819, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 11261792 and 11261801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11261891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5630910 + 5630911.

It is an arithmetic number, because the mean of its divisors is an integer number (5630911).

Almost surely, 2^11261821 is an apocalyptic number.

It is an amenable number.

11261821 is a deficient number, since it is larger than the sum of its proper divisors (1).

11261821 is an equidigital number, since it uses as much as digits as its factorization.

11261821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 22.

The square root of 11261821 is about 3355.8636742275. The cubic root of 11261821 is about 224.1486908713.

The spelling of 11261821 in words is "eleven million, two hundred sixty-one thousand, eight hundred twenty-one".