688046321 has 4 divisors (see below), whose sum is σ = 728519652. Its totient is φ = 647572992.

The previous prime is 688046299. The next prime is 688046329. The reversal of 688046321 is 123640886.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 310288225 + 377758096 = 17615^2 + 19436^2 .

It is a cyclic number.

It is not a de Polignac number, because 688046321 - 2¹⁰ = 688045297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688046329) 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 3 ways as a sum of consecutive naturals, for example, 20236640 + ... + 20236673.

It is an arithmetic number, because the mean of its divisors is an integer number (182129913).

Almost surely, 2^688046321 is an apocalyptic number.

It is an amenable number.

688046321 is a deficient number, since it is larger than the sum of its proper divisors (40473331).

688046321 is a wasteful number, since it uses less digits than its factorization.

688046321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40473330.

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 688046321 is about 26230.6370681308. The cubic root of 688046321 is about 882.8208041682.

The spelling of 688046321 in words is "six hundred eighty-eight million, forty-six thousand, three hundred twenty-one".