20516473 has 2 divisors, whose sum is σ = 20516474. Its totient is φ = 20516472.

The previous prime is 20516471. The next prime is 20516519. The reversal of 20516473 is 37461502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20502784 + 13689 = 4528^2 + 117^2 .

It is a cyclic number.

It is not a de Polignac number, because 20516473 - 2¹ = 20516471 is a prime.

Together with 20516471, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20516471) 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, 10258236 + 10258237.

It is an arithmetic number, because the mean of its divisors is an integer number (10258237).

Almost surely, 2^20516473 is an apocalyptic number.

It is an amenable number.

20516473 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516473 is an equidigital number, since it uses as much as digits as its factorization.

20516473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20516473 is about 4529.5113422973. The cubic root of 20516473 is about 273.7584716907.

Adding to 20516473 its reverse (37461502), we get a palindrome (57977975).

The spelling of 20516473 in words is "twenty million, five hundred sixteen thousand, four hundred seventy-three".