20561069 has 2 divisors, whose sum is σ = 20561070. Its totient is φ = 20561068.

The previous prime is 20561053. The next prime is 20561081. The reversal of 20561069 is 96016502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14160169 + 6400900 = 3763^2 + 2530^2 .

It is a cyclic number.

It is not a de Polignac number, because 20561069 - 2⁴ = 20561053 is a prime.

It is a super-2 number, since 2×20561069² = 845515116845522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20561369) 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, 10280534 + 10280535.

It is an arithmetic number, because the mean of its divisors is an integer number (10280535).

Almost surely, 2^20561069 is an apocalyptic number.

It is an amenable number.

20561069 is a deficient number, since it is larger than the sum of its proper divisors (1).

20561069 is an equidigital number, since it uses as much as digits as its factorization.

20561069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 20561069 is about 4534.4314968913. The cubic root of 20561069 is about 273.9566814854.

It can be divided in two parts, 2056 and 1069, that added together give a 5-th power (3125 = 5⁵).

The spelling of 20561069 in words is "twenty million, five hundred sixty-one thousand, sixty-nine".