681987593 has 8 divisors (see below), whose sum is σ = 779581440. Its totient is φ = 584435520.

The previous prime is 681987497. The next prime is 681987601. The reversal of 681987593 is 395789186.

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 681987593 - 2⁸ = 681987337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681987893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42353 + ... + 56193.

It is an arithmetic number, because the mean of its divisors is an integer number (97447680).

Almost surely, 2^681987593 is an apocalyptic number.

It is an amenable number.

681987593 is a deficient number, since it is larger than the sum of its proper divisors (97593847).

681987593 is a wasteful number, since it uses less digits than its factorization.

681987593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20887.

The product of its digits is 3265920, while the sum is 56.

The square root of 681987593 is about 26114.8921690288. The cubic root of 681987593 is about 880.2218763018.

The spelling of 681987593 in words is "six hundred eighty-one million, nine hundred eighty-seven thousand, five hundred ninety-three".