20881902497 has 2 divisors, whose sum is σ = 20881902498. Its totient is φ = 20881902496.

The previous prime is 20881902479. The next prime is 20881902541. The reversal of 20881902497 is 79420918802.

Together with previous prime (20881902479) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17314349056 + 3567553441 = 131584^2 + 59729^2 .

It is a cyclic number.

It is not a de Polignac number, because 20881902497 - 2⁸ = 20881902241 is a prime.

It is not a weakly prime, because it can be changed into another prime (20881902407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10440951248 + 10440951249.

It is an arithmetic number, because the mean of its divisors is an integer number (10440951249).

Almost surely, 2^20881902497 is an apocalyptic number.

It is an amenable number.

20881902497 is a deficient number, since it is larger than the sum of its proper divisors (1).

20881902497 is an equidigital number, since it uses as much as digits as its factorization.

20881902497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 50.

The spelling of 20881902497 in words is "twenty billion, eight hundred eighty-one million, nine hundred two thousand, four hundred ninety-seven".