20988557132717 has 2 divisors, whose sum is σ = 20988557132718. Its totient is φ = 20988557132716.

The previous prime is 20988557132677. The next prime is 20988557132773. The reversal of 20988557132717 is 71723175588902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14704816718596 + 6283740414121 = 3834686^2 + 2506739^2 .

It is a cyclic number.

It is not a de Polignac number, because 20988557132717 - 2¹⁰ = 20988557131693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20988557122717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494278566358 + 10494278566359.

It is an arithmetic number, because the mean of its divisors is an integer number (10494278566359).

Almost surely, 2^{20988557132717} is an apocalyptic number.

It is an amenable number.

20988557132717 is a deficient number, since it is larger than the sum of its proper divisors (1).

20988557132717 is an equidigital number, since it uses as much as digits as its factorization.

20988557132717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 59270400, while the sum is 65.

The spelling of 20988557132717 in words is "twenty trillion, nine hundred eighty-eight billion, five hundred fifty-seven million, one hundred thirty-two thousand, seven hundred seventeen".