20515340473 has 2 divisors, whose sum is σ = 20515340474. Its totient is φ = 20515340472.

The previous prime is 20515340441. The next prime is 20515340513. The reversal of 20515340473 is 37404351502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18076264704 + 2439075769 = 134448^2 + 49387^2 .

It is a cyclic number.

It is not a de Polignac number, because 20515340473 - 2⁵ = 20515340441 is a prime.

It is a super-2 number, since 2×20515340473² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20515346473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10257670236 + 10257670237.

It is an arithmetic number, because the mean of its divisors is an integer number (10257670237).

Almost surely, 2^20515340473 is an apocalyptic number.

It is an amenable number.

20515340473 is a deficient number, since it is larger than the sum of its proper divisors (1).

20515340473 is an equidigital number, since it uses as much as digits as its factorization.

20515340473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 50400, while the sum is 34.

Adding to 20515340473 its reverse (37404351502), we get a palindrome (57919691975).

The spelling of 20515340473 in words is "twenty billion, five hundred fifteen million, three hundred forty thousand, four hundred seventy-three".