681921799 has 48 divisors (see below), whose sum is σ = 844814880. Its totient is φ = 545218560.

The previous prime is 681921781. The next prime is 681921811. The reversal of 681921799 is 997129186.

It is not a de Polignac number, because 681921799 - 2⁷ = 681921671 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681921719) 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 47 ways as a sum of consecutive naturals, for example, 2926587 + ... + 2926819.

It is an arithmetic number, because the mean of its divisors is an integer number (17600310).

Almost surely, 2^681921799 is an apocalyptic number.

681921799 is a deficient number, since it is larger than the sum of its proper divisors (162893081).

681921799 is a wasteful number, since it uses less digits than its factorization.

681921799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340 (or 323 counting only the distinct ones).

The product of its digits is 489888, while the sum is 52.

The square root of 681921799 is about 26113.6324359519. The cubic root of 681921799 is about 880.1935692469.

The spelling of 681921799 in words is "six hundred eighty-one million, nine hundred twenty-one thousand, seven hundred ninety-nine".