808166521 has 2 divisors, whose sum is σ = 808166522. Its totient is φ = 808166520.

The previous prime is 808166509. The next prime is 808166533. The reversal of 808166521 is 125661808.

It is a balanced prime because it is at equal distance from previous prime (808166509) and next prime (808166533).

It can be written as a sum of positive squares in only one way, i.e., 651015225 + 157151296 = 25515^2 + 12536^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-808166521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (808166581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404083260 + 404083261.

It is an arithmetic number, because the mean of its divisors is an integer number (404083261).

Almost surely, 2^808166521 is an apocalyptic number.

It is an amenable number.

808166521 is a deficient number, since it is larger than the sum of its proper divisors (1).

808166521 is an equidigital number, since it uses as much as digits as its factorization.

808166521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 808166521 is about 28428.2697503735. The cubic root of 808166521 is about 931.4658814793.

The spelling of 808166521 in words is "eight hundred eight million, one hundred sixty-six thousand, five hundred twenty-one".