8351217521 has 2 divisors, whose sum is σ = 8351217522. Its totient is φ = 8351217520.

The previous prime is 8351217517. The next prime is 8351217527. The reversal of 8351217521 is 1257121538.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8321088400 + 30129121 = 91220^2 + 5489^2 .

It is a cyclic number.

It is not a de Polignac number, because 8351217521 - 2² = 8351217517 is a prime.

It is not a weakly prime, because it can be changed into another prime (8351217527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4175608760 + 4175608761.

It is an arithmetic number, because the mean of its divisors is an integer number (4175608761).

Almost surely, 2^8351217521 is an apocalyptic number.

It is an amenable number.

8351217521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8351217521 is an equidigital number, since it uses as much as digits as its factorization.

8351217521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16800, while the sum is 35.

The square root of 8351217521 is about 91384.9961481643. The cubic root of 8351217521 is about 2028.8499654616.

The spelling of 8351217521 in words is "eight billion, three hundred fifty-one million, two hundred seventeen thousand, five hundred twenty-one".