68816639 has 4 divisors (see below), whose sum is σ = 69120024. Its totient is φ = 68513256.

The previous prime is 68816609. The next prime is 68816647. The reversal of 68816639 is 93661886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93661886 = 2 ⋅46830943.

It is a cyclic number.

It is not a de Polignac number, because 68816639 - 2¹² = 68812543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 68816593 and 68816602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68816609) 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, 151352 + ... + 151805.

It is an arithmetic number, because the mean of its divisors is an integer number (17280006).

Almost surely, 2^68816639 is an apocalyptic number.

68816639 is a deficient number, since it is larger than the sum of its proper divisors (303385).

68816639 is a wasteful number, since it uses less digits than its factorization.

68816639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303384.

The product of its digits is 373248, while the sum is 47.

The square root of 68816639 is about 8295.5794854850. The cubic root of 68816639 is about 409.7929531643.

The spelling of 68816639 in words is "sixty-eight million, eight hundred sixteen thousand, six hundred thirty-nine".