6616215464561 has 2 divisors, whose sum is σ = 6616215464562. Its totient is φ = 6616215464560.

The previous prime is 6616215464503. The next prime is 6616215464567. The reversal of 6616215464561 is 1654645126166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6532911073936 + 83304390625 = 2555956^2 + 288625^2 .

It is a cyclic number.

It is not a de Polignac number, because 6616215464561 - 2⁶ = 6616215464497 is a prime.

It is a super-2 number, since 2×6616215464561² (a number of 26 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6616215464567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3308107732280 + 3308107732281.

It is an arithmetic number, because the mean of its divisors is an integer number (3308107732281).

Almost surely, 2^{6616215464561} is an apocalyptic number.

It is an amenable number.

6616215464561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6616215464561 is an equidigital number, since it uses as much as digits as its factorization.

6616215464561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6220800, while the sum is 53.

The spelling of 6616215464561 in words is "six trillion, six hundred sixteen billion, two hundred fifteen million, four hundred sixty-four thousand, five hundred sixty-one".