68993891 has 4 divisors (see below), whose sum is σ = 69013032. Its totient is φ = 68974752.

The previous prime is 68993861. The next prime is 68993909. The reversal of 68993891 is 19839986.

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 68993891 - 2¹⁰ = 68992867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68993831) 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, 2345 + ... + 11978.

It is an arithmetic number, because the mean of its divisors is an integer number (17253258).

Almost surely, 2^68993891 is an apocalyptic number.

68993891 is a deficient number, since it is larger than the sum of its proper divisors (19141).

68993891 is a wasteful number, since it uses less digits than its factorization.

68993891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19140.

The product of its digits is 839808, while the sum is 53.

The square root of 68993891 is about 8306.2561361904. The cubic root of 68993891 is about 410.1444880399.

The spelling of 68993891 in words is "sixty-eight million, nine hundred ninety-three thousand, eight hundred ninety-one".