68129521 has 4 divisors (see below), whose sum is σ = 68992000. Its totient is φ = 67267044.

The previous prime is 68129491. The next prime is 68129527. The reversal of 68129521 is 12592186.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 68129521 - 2⁷ = 68129393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68129527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431121 + ... + 431278.

It is an arithmetic number, because the mean of its divisors is an integer number (17248000).

Almost surely, 2^68129521 is an apocalyptic number.

It is an amenable number.

68129521 is a deficient number, since it is larger than the sum of its proper divisors (862479).

68129521 is an equidigital number, since it uses as much as digits as its factorization.

68129521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862478.

The product of its digits is 8640, while the sum is 34.

The square root of 68129521 is about 8254.0608793490. The cubic root of 68129521 is about 408.4244929149.

The spelling of 68129521 in words is "sixty-eight million, one hundred twenty-nine thousand, five hundred twenty-one".