68978539 has 4 divisors (see below), whose sum is σ = 78832624. Its totient is φ = 59124456.

The previous prime is 68978527. The next prime is 68978549. The reversal of 68978539 is 93587986.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 68978539 - 2⁷ = 68978411 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 68978539.

It is not an unprimeable number, because it can be changed into a prime (68978549) 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, 4927032 + ... + 4927045.

It is an arithmetic number, because the mean of its divisors is an integer number (19708156).

Almost surely, 2^68978539 is an apocalyptic number.

68978539 is a deficient number, since it is larger than the sum of its proper divisors (9854085).

68978539 is an equidigital number, since it uses as much as digits as its factorization.

68978539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9854084.

The product of its digits is 3265920, while the sum is 55.

The square root of 68978539 is about 8305.3319620591. The cubic root of 68978539 is about 410.1140650311.

The spelling of 68978539 in words is "sixty-eight million, nine hundred seventy-eight thousand, five hundred thirty-nine".