8216657603509 has 2 divisors, whose sum is σ = 8216657603510. Its totient is φ = 8216657603508.

The previous prime is 8216657603507. The next prime is 8216657603569. The reversal of 8216657603509 is 9053067566128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6301340001009 + 1915317602500 = 2510247^2 + 1383950^2 .

It is a cyclic number.

It is not a de Polignac number, because 8216657603509 - 2¹ = 8216657603507 is a prime.

It is a super-2 number, since 2×8216657603509² (a number of 27 digits) contains 22 as substring.

Together with 8216657603507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8216657603507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4108328801754 + 4108328801755.

It is an arithmetic number, because the mean of its divisors is an integer number (4108328801755).

Almost surely, 2^{8216657603509} is an apocalyptic number.

It is an amenable number.

8216657603509 is a deficient number, since it is larger than the sum of its proper divisors (1).

8216657603509 is an equidigital number, since it uses as much as digits as its factorization.

8216657603509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16329600, while the sum is 58.

The spelling of 8216657603509 in words is "eight trillion, two hundred sixteen billion, six hundred fifty-seven million, six hundred three thousand, five hundred nine".