20516225514487 has 2 divisors, whose sum is σ = 20516225514488. Its totient is φ = 20516225514486.

The previous prime is 20516225514443. The next prime is 20516225514493. The reversal of 20516225514487 is 78441552261502.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20516225514487 is a prime.

It is a super-2 number, since 2×20516225514487² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20516225584487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258112757243 + 10258112757244.

It is an arithmetic number, because the mean of its divisors is an integer number (10258112757244).

Almost surely, 2^{20516225514487} is an apocalyptic number.

20516225514487 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516225514487 is an equidigital number, since it uses as much as digits as its factorization.

20516225514487 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376000, while the sum is 52.

Adding to 20516225514487 its reverse (78441552261502), we get a palindrome (98957777775989).

The spelling of 20516225514487 in words is "twenty trillion, five hundred sixteen billion, two hundred twenty-five million, five hundred fourteen thousand, four hundred eighty-seven".