20563237 has 2 divisors, whose sum is σ = 20563238. Its totient is φ = 20563236.

The previous prime is 20563189. The next prime is 20563259. The reversal of 20563237 is 73236502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17355556 + 3207681 = 4166^2 + 1791^2 .

It is a cyclic number.

It is not a de Polignac number, because 20563237 - 2²³ = 12174629 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 (20563337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10281618 + 10281619.

It is an arithmetic number, because the mean of its divisors is an integer number (10281619).

Almost surely, 2^20563237 is an apocalyptic number.

It is an amenable number.

20563237 is a deficient number, since it is larger than the sum of its proper divisors (1).

20563237 is an equidigital number, since it uses as much as digits as its factorization.

20563237 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 28.

The square root of 20563237 is about 4534.6705503267. The cubic root of 20563237 is about 273.9663099928.

Adding to 20563237 its reverse (73236502), we get a palindrome (93799739).

The spelling of 20563237 in words is "twenty million, five hundred sixty-three thousand, two hundred thirty-seven".