68521475641 has 2 divisors, whose sum is σ = 68521475642. Its totient is φ = 68521475640.

The previous prime is 68521475567. The next prime is 68521475647. The reversal of 68521475641 is 14657412586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54903519225 + 13617956416 = 234315^2 + 116696^2 .

It is a cyclic number.

It is not a de Polignac number, because 68521475641 - 2²¹ = 68519378489 is a prime.

It is not a weakly prime, because it can be changed into another prime (68521475647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34260737820 + 34260737821.

It is an arithmetic number, because the mean of its divisors is an integer number (34260737821).

Almost surely, 2^68521475641 is an apocalyptic number.

It is an amenable number.

68521475641 is a deficient number, since it is larger than the sum of its proper divisors (1).

68521475641 is an equidigital number, since it uses as much as digits as its factorization.

68521475641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1612800, while the sum is 49.

The spelling of 68521475641 in words is "sixty-eight billion, five hundred twenty-one million, four hundred seventy-five thousand, six hundred forty-one".