680891918 has 32 divisors (see below), whose sum is σ = 1184053248. Its totient is φ = 287640000.

The previous prime is 680891909. The next prime is 680891927. The reversal of 680891918 is 819198086.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (680891909) and next prime (680891927).

It is a super-2 number, since 2×680891918² = 927227607995437448, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 288443 + ... + 290793.

It is an arithmetic number, because the mean of its divisors is an integer number (37001664).

Almost surely, 2^680891918 is an apocalyptic number.

680891918 is a deficient number, since it is larger than the sum of its proper divisors (503161330).

680891918 is a wasteful number, since it uses less digits than its factorization.

680891918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2648.

The product of its (nonzero) digits is 248832, while the sum is 50.

The square root of 680891918 is about 26093.9057636069. The cubic root of 680891918 is about 879.7502381757.

It can be divided in two parts, 68089 and 1918, that added together give a palindrome (70007).

The spelling of 680891918 in words is "six hundred eighty million, eight hundred ninety-one thousand, nine hundred eighteen".