20600561 has 2 divisors, whose sum is σ = 20600562. Its totient is φ = 20600560.

The previous prime is 20600551. The next prime is 20600597. The reversal of 20600561 is 16500602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15649936 + 4950625 = 3956^2 + 2225^2 .

It is a cyclic number.

It is not a de Polignac number, because 20600561 - 2¹⁴ = 20584177 is a prime.

It is a super-2 number, since 2×20600561² = 848766227029442, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20600501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10300280 + 10300281.

It is an arithmetic number, because the mean of its divisors is an integer number (10300281).

Almost surely, 2^20600561 is an apocalyptic number.

It is an amenable number.

20600561 is a deficient number, since it is larger than the sum of its proper divisors (1).

20600561 is an equidigital number, since it uses as much as digits as its factorization.

20600561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20600561 is about 4538.7840882774. The cubic root of 20600561 is about 274.1319670836.

The spelling of 20600561 in words is "twenty million, six hundred thousand, five hundred sixty-one".