20323561 has 2 divisors, whose sum is σ = 20323562. Its totient is φ = 20323560.

The previous prime is 20323547. The next prime is 20323601. The reversal of 20323561 is 16532302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19713600 + 609961 = 4440^2 + 781^2 .

It is a cyclic number.

It is not a de Polignac number, because 20323561 - 2⁵ = 20323529 is a prime.

It is not a weakly prime, because it can be changed into another prime (20323531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10161780 + 10161781.

It is an arithmetic number, because the mean of its divisors is an integer number (10161781).

Almost surely, 2^20323561 is an apocalyptic number.

It is an amenable number.

20323561 is a deficient number, since it is larger than the sum of its proper divisors (1).

20323561 is an equidigital number, since it uses as much as digits as its factorization.

20323561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 20323561 is about 4508.1660350968. The cubic root of 20323561 is about 272.8977375084.

Adding to 20323561 its reverse (16532302), we get a palindrome (36855863).

The spelling of 20323561 in words is "twenty million, three hundred twenty-three thousand, five hundred sixty-one".