68129874289 has 3 divisors (see below), whose sum is σ = 68130135307. Its totient is φ = 68129613272.

The previous prime is 68129874287. The next prime is 68129874313. The reversal of 68129874289 is 98247892186.

It is a happy number.

The square root of 68129874289 is 261017.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 66123551025 + 2006323264 = 257145^2 + 44792^2 .

It is not a de Polignac number, because 68129874289 - 2¹ = 68129874287 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 68129874289.

It is not an unprimeable number, because it can be changed into a prime (68129874287) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 130509 + ... + 391525.

Almost surely, 2^68129874289 is an apocalyptic number.

68129874289 is the 261017-th square number.

68129874289 is the 130509-th centered octagonal number.

It is an amenable number.

68129874289 is a deficient number, since it is larger than the sum of its proper divisors (261018).

68129874289 is an frugal number, since it uses more digits than its factorization.

68129874289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522034 (or 261017 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 64.

Multiplying 68129874289 by its sum of digits (64), we get a square (4360311954496 = 2088136²).

The spelling of 68129874289 in words is "sixty-eight billion, one hundred twenty-nine million, eight hundred seventy-four thousand, two hundred eighty-nine".