68129281 has 4 divisors (see below), whose sum is σ = 74322864. Its totient is φ = 61935700.

The previous prime is 68129279. The next prime is 68129287. The reversal of 68129281 is 18292186.

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 68129281 - 2¹ = 68129279 is a prime.

It is a super-2 number, since 2×68129281² = 9283197859153922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 68129281.

It is not an unprimeable number, because it can be changed into a prime (68129287) 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, 3096775 + ... + 3096796.

It is an arithmetic number, because the mean of its divisors is an integer number (18580716).

Almost surely, 2^68129281 is an apocalyptic number.

It is an amenable number.

68129281 is a deficient number, since it is larger than the sum of its proper divisors (6193583).

68129281 is a wasteful number, since it uses less digits than its factorization.

68129281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6193582.

The product of its digits is 13824, while the sum is 37.

The square root of 68129281 is about 8254.0463410378. The cubic root of 68129281 is about 408.4240133284.

The spelling of 68129281 in words is "sixty-eight million, one hundred twenty-nine thousand, two hundred eighty-one".