68418991 has 4 divisors (see below), whose sum is σ = 68801400. Its totient is φ = 68036584.

The previous prime is 68418989. The next prime is 68419009. The reversal of 68418991 is 19981486.

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 68418991 - 2¹ = 68418989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68418391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190936 + ... + 191293.

It is an arithmetic number, because the mean of its divisors is an integer number (17200350).

Almost surely, 2^68418991 is an apocalyptic number.

68418991 is a deficient number, since it is larger than the sum of its proper divisors (382409).

68418991 is a wasteful number, since it uses less digits than its factorization.

68418991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382408.

The product of its digits is 124416, while the sum is 46.

The square root of 68418991 is about 8271.5772981941. The cubic root of 68418991 is about 409.0021161887.

The spelling of 68418991 in words is "sixty-eight million, four hundred eighteen thousand, nine hundred ninety-one".