68559521 has 4 divisors (see below), whose sum is σ = 72592452. Its totient is φ = 64526592.

The previous prime is 68559499. The next prime is 68559523. The reversal of 68559521 is 12595586.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12595586 = 2 ⋅6297793.

It can be written as a sum of positive squares in 2 ways, for example, as 45711121 + 22848400 = 6761^2 + 4780^2 .

It is a cyclic number.

It is not a de Polignac number, because 68559521 - 2⁶ = 68559457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (68559523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2016440 + ... + 2016473.

It is an arithmetic number, because the mean of its divisors is an integer number (18148113).

Almost surely, 2^68559521 is an apocalyptic number.

It is an amenable number.

68559521 is a deficient number, since it is larger than the sum of its proper divisors (4032931).

68559521 is a wasteful number, since it uses less digits than its factorization.

68559521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4032930.

The product of its digits is 108000, while the sum is 41.

The square root of 68559521 is about 8280.0676929600. The cubic root of 68559521 is about 409.2819496068.

It can be divided in two parts, 685 and 59521, that added together give a palindrome (60206).

The spelling of 68559521 in words is "sixty-eight million, five hundred fifty-nine thousand, five hundred twenty-one".