681593939 has 8 divisors (see below), whose sum is σ = 747874512. Its totient is φ = 617292000.

The previous prime is 681593921. The next prime is 681593981. The reversal of 681593939 is 939395186.

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

It is not a de Polignac number, because 681593939 - 2¹⁶ = 681528403 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681593839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 493937 + ... + 495314.

It is an arithmetic number, because the mean of its divisors is an integer number (93484314).

Almost surely, 2^681593939 is an apocalyptic number.

681593939 is a deficient number, since it is larger than the sum of its proper divisors (66280573).

681593939 is a wasteful number, since it uses less digits than its factorization.

681593939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989317.

The product of its digits is 1574640, while the sum is 53.

The square root of 681593939 is about 26107.3541171832. The cubic root of 681593939 is about 880.0524843869.

The spelling of 681593939 in words is "six hundred eighty-one million, five hundred ninety-three thousand, nine hundred thirty-nine".