688169520281 has 2 divisors, whose sum is σ = 688169520282. Its totient is φ = 688169520280.

The previous prime is 688169520209. The next prime is 688169520301. The reversal of 688169520281 is 182025961886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 454195123600 + 233974396681 = 673940^2 + 483709^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688169520281 is a prime.

It is a super-2 number, since 2×688169520281² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (688169520481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344084760140 + 344084760141.

It is an arithmetic number, because the mean of its divisors is an integer number (344084760141).

Almost surely, 2^688169520281 is an apocalyptic number.

It is an amenable number.

688169520281 is a deficient number, since it is larger than the sum of its proper divisors (1).

688169520281 is an equidigital number, since it uses as much as digits as its factorization.

688169520281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3317760, while the sum is 56.

The spelling of 688169520281 in words is "six hundred eighty-eight billion, one hundred sixty-nine million, five hundred twenty thousand, two hundred eighty-one".