68212515517 has 2 divisors, whose sum is σ = 68212515518. Its totient is φ = 68212515516.

The previous prime is 68212515491. The next prime is 68212515523. The reversal of 68212515517 is 71551521286.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66475793241 + 1736722276 = 257829^2 + 41674^2 .

It is a cyclic number.

It is not a de Polignac number, because 68212515517 - 2²⁷ = 68078297789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68212515617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34106257758 + 34106257759.

It is an arithmetic number, because the mean of its divisors is an integer number (34106257759).

Almost surely, 2^68212515517 is an apocalyptic number.

It is an amenable number.

68212515517 is a deficient number, since it is larger than the sum of its proper divisors (1).

68212515517 is an equidigital number, since it uses as much as digits as its factorization.

68212515517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 168000, while the sum is 43.

The spelling of 68212515517 in words is "sixty-eight billion, two hundred twelve million, five hundred fifteen thousand, five hundred seventeen".