681953593 has 4 divisors (see below), whose sum is σ = 703952128. Its totient is φ = 659955060.

The previous prime is 681953579. The next prime is 681953633. The reversal of 681953593 is 395359186.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 681953593 - 2⁹ = 681953081 is a prime.

It is a super-3 number, since 3×681953593³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681953513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10999221 + ... + 10999282.

It is an arithmetic number, because the mean of its divisors is an integer number (175988032).

Almost surely, 2^681953593 is an apocalyptic number.

It is an amenable number.

681953593 is a deficient number, since it is larger than the sum of its proper divisors (21998535).

681953593 is a wasteful number, since it uses less digits than its factorization.

681953593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21998534.

The product of its digits is 874800, while the sum is 49.

The square root of 681953593 is about 26114.2411913500. The cubic root of 681953593 is about 880.2072484496.

The spelling of 681953593 in words is "six hundred eighty-one million, nine hundred fifty-three thousand, five hundred ninety-three".