11561021 has 2 divisors, whose sum is σ = 11561022. Its totient is φ = 11561020.

The previous prime is 11560981. The next prime is 11561027. The reversal of 11561021 is 12016511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10725625 + 835396 = 3275^2 + 914^2 .

It is a cyclic number.

It is not a de Polignac number, because 11561021 - 2⁶ = 11560957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11561027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5780510 + 5780511.

It is an arithmetic number, because the mean of its divisors is an integer number (5780511).

Almost surely, 2^11561021 is an apocalyptic number.

It is an amenable number.

11561021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11561021 is an equidigital number, since it uses as much as digits as its factorization.

11561021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 11561021 is about 3400.1501437437. The cubic root of 11561021 is about 226.1164004761.

Adding to 11561021 its reverse (12016511), we get a palindrome (23577532).

The spelling of 11561021 in words is "eleven million, five hundred sixty-one thousand, twenty-one".