8495639256521 has 2 divisors, whose sum is σ = 8495639256522. Its totient is φ = 8495639256520.

The previous prime is 8495639256479. The next prime is 8495639256523. The reversal of 8495639256521 is 1256529365948.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5855456238025 + 2640183018496 = 2419805^2 + 1624864^2 .

It is a cyclic number.

It is not a de Polignac number, because 8495639256521 - 2⁶ = 8495639256457 is a prime.

Together with 8495639256523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8495639256523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4247819628260 + 4247819628261.

It is an arithmetic number, because the mean of its divisors is an integer number (4247819628261).

Almost surely, 2^{8495639256521} is an apocalyptic number.

It is an amenable number.

8495639256521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8495639256521 is an equidigital number, since it uses as much as digits as its factorization.

8495639256521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968000, while the sum is 65.

The spelling of 8495639256521 in words is "eight trillion, four hundred ninety-five billion, six hundred thirty-nine million, two hundred fifty-six thousand, five hundred twenty-one".