688661723 has 8 divisors (see below), whose sum is σ = 716230080. Its totient is φ = 661564800.

The previous prime is 688661693. The next prime is 688661749. The reversal of 688661723 is 327166886.

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

It is a cyclic number.

It is not a de Polignac number, because 688661723 - 2¹⁶ = 688596187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688661773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114878 + ... + 120723.

It is an arithmetic number, because the mean of its divisors is an integer number (89528760).

Almost surely, 2^688661723 is an apocalyptic number.

688661723 is a deficient number, since it is larger than the sum of its proper divisors (27568357).

688661723 is a wasteful number, since it uses less digits than its factorization.

688661723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235717.

The product of its digits is 580608, while the sum is 47.

The square root of 688661723 is about 26242.3650420460. The cubic root of 688661723 is about 883.0839297632.

The spelling of 688661723 in words is "six hundred eighty-eight million, six hundred sixty-one thousand, seven hundred twenty-three".