68523897581 has 2 divisors, whose sum is σ = 68523897582. Its totient is φ = 68523897580.

The previous prime is 68523897553. The next prime is 68523897683. The reversal of 68523897581 is 18579832586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67894640356 + 629257225 = 260566^2 + 25085^2 .

It is a cyclic number.

It is not a de Polignac number, because 68523897581 - 2¹⁰ = 68523896557 is a prime.

It is a super-2 number, since 2×68523897581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68523897511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34261948790 + 34261948791.

It is an arithmetic number, because the mean of its divisors is an integer number (34261948791).

Almost surely, 2^68523897581 is an apocalyptic number.

It is an amenable number.

68523897581 is a deficient number, since it is larger than the sum of its proper divisors (1).

68523897581 is an equidigital number, since it uses as much as digits as its factorization.

68523897581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29030400, while the sum is 62.

The spelling of 68523897581 in words is "sixty-eight billion, five hundred twenty-three million, eight hundred ninety-seven thousand, five hundred eighty-one".