20915502497 has 2 divisors, whose sum is σ = 20915502498. Its totient is φ = 20915502496.

The previous prime is 20915502469. The next prime is 20915502521. The reversal of 20915502497 is 79420551902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19477272721 + 1438229776 = 139561^2 + 37924^2 .

It is a cyclic number.

It is not a de Polignac number, because 20915502497 - 2¹⁶ = 20915436961 is a prime.

It is not a weakly prime, because it can be changed into another prime (20915502997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10457751248 + 10457751249.

It is an arithmetic number, because the mean of its divisors is an integer number (10457751249).

Almost surely, 2^20915502497 is an apocalyptic number.

It is an amenable number.

20915502497 is a deficient number, since it is larger than the sum of its proper divisors (1).

20915502497 is an equidigital number, since it uses as much as digits as its factorization.

20915502497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 226800, while the sum is 44.

The spelling of 20915502497 in words is "twenty billion, nine hundred fifteen million, five hundred two thousand, four hundred ninety-seven".