13561021 has 2 divisors, whose sum is σ = 13561022. Its totient is φ = 13561020.

The previous prime is 13561013. The next prime is 13561027. The reversal of 13561021 is 12016531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7868025 + 5692996 = 2805^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 13561021 - 2³ = 13561013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13561021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13561027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6780510 + 6780511.

It is an arithmetic number, because the mean of its divisors is an integer number (6780511).

Almost surely, 2^13561021 is an apocalyptic number.

It is an amenable number.

13561021 is a deficient number, since it is larger than the sum of its proper divisors (1).

13561021 is an equidigital number, since it uses as much as digits as its factorization.

13561021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 13561021 is about 3682.5291580651. The cubic root of 13561021 is about 238.4683771272.

Adding to 13561021 its reverse (12016531), we get a palindrome (25577552).

The spelling of 13561021 in words is "thirteen million, five hundred sixty-one thousand, twenty-one".