8689351820521 has 2 divisors, whose sum is σ = 8689351820522. Its totient is φ = 8689351820520.

The previous prime is 8689351820519. The next prime is 8689351820551. The reversal of 8689351820521 is 1250281539868.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4810279765225 + 3879072055296 = 2193235^2 + 1969536^2 .

It is a cyclic number.

It is not a de Polignac number, because 8689351820521 - 2¹ = 8689351820519 is a prime.

It is a super-2 number, since 2×8689351820521² (a number of 27 digits) contains 22 as substring.

Together with 8689351820519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (8689351820551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4344675910260 + 4344675910261.

It is an arithmetic number, because the mean of its divisors is an integer number (4344675910261).

Almost surely, 2^{8689351820521} is an apocalyptic number.

It is an amenable number.

8689351820521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8689351820521 is an equidigital number, since it uses as much as digits as its factorization.

8689351820521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8294400, while the sum is 58.

The spelling of 8689351820521 in words is "eight trillion, six hundred eighty-nine billion, three hundred fifty-one million, eight hundred twenty thousand, five hundred twenty-one".