681304523 has 4 divisors (see below), whose sum is σ = 688959720. Its totient is φ = 673649328.

The previous prime is 681304501. The next prime is 681304537. The reversal of 681304523 is 325403186.

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 681304523 - 2¹² = 681300427 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 681304523.

It is not an unprimeable number, because it can be changed into a prime (681304123) 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, 3827465 + ... + 3827642.

It is an arithmetic number, because the mean of its divisors is an integer number (172239930).

Almost surely, 2^681304523 is an apocalyptic number.

681304523 is a deficient number, since it is larger than the sum of its proper divisors (7655197).

681304523 is an equidigital number, since it uses as much as digits as its factorization.

681304523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7655196.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 681304523 is about 26101.8107226300. The cubic root of 681304523 is about 879.9279051647.

The spelling of 681304523 in words is "six hundred eighty-one million, three hundred four thousand, five hundred twenty-three".