681681805 has 8 divisors (see below), whose sum is σ = 934877952. Its totient is φ = 467438928.

The previous prime is 681681779. The next prime is 681681839. The reversal of 681681805 is 508186186.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681681805 - 2¹³ = 681673613 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 9738277 + ... + 9738346.

It is an arithmetic number, because the mean of its divisors is an integer number (116859744).

Almost surely, 2^681681805 is an apocalyptic number.

It is an amenable number.

681681805 is a deficient number, since it is larger than the sum of its proper divisors (253196147).

681681805 is a wasteful number, since it uses less digits than its factorization.

681681805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19476635.

The product of its (nonzero) digits is 92160, while the sum is 43.

The square root of 681681805 is about 26109.0368455062. The cubic root of 681681805 is about 880.0902993598.

The spelling of 681681805 in words is "six hundred eighty-one million, six hundred eighty-one thousand, eight hundred five".