68991719 has 4 divisors (see below), whose sum is σ = 69090840. Its totient is φ = 68892600.

The previous prime is 68991707. The next prime is 68991731. The reversal of 68991719 is 91719986.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91719986 = 2 ⋅45859993.

It is an interprime number because it is at equal distance from previous prime (68991707) and next prime (68991731).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68991719 is a prime.

It is a super-2 number, since 2×68991719² = 9519714581149922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68991739) 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, 48509 + ... + 49910.

It is an arithmetic number, because the mean of its divisors is an integer number (17272710).

Almost surely, 2^68991719 is an apocalyptic number.

68991719 is a deficient number, since it is larger than the sum of its proper divisors (99121).

68991719 is an equidigital number, since it uses as much as digits as its factorization.

68991719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99120.

The product of its digits is 244944, while the sum is 50.

The square root of 68991719 is about 8306.1253903369. The cubic root of 68991719 is about 410.1401840686.

The spelling of 68991719 in words is "sixty-eight million, nine hundred ninety-one thousand, seven hundred nineteen".