681664343 has 4 divisors (see below), whose sum is σ = 705170040. Its totient is φ = 658158648.

The previous prime is 681664339. The next prime is 681664367. The reversal of 681664343 is 343466186.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 681664343 - 2² = 681664339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 681664343.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681663343) 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, 11752805 + ... + 11752862.

It is an arithmetic number, because the mean of its divisors is an integer number (176292510).

Almost surely, 2^681664343 is an apocalyptic number.

681664343 is a deficient number, since it is larger than the sum of its proper divisors (23505697).

681664343 is a wasteful number, since it uses less digits than its factorization.

681664343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23505696.

The product of its digits is 248832, while the sum is 41.

The square root of 681664343 is about 26108.7024380761. The cubic root of 681664343 is about 880.0827844812.

The spelling of 681664343 in words is "six hundred eighty-one million, six hundred sixty-four thousand, three hundred forty-three".