688549723 has 4 divisors (see below), whose sum is σ = 688678848. Its totient is φ = 688420600.

The previous prime is 688549709. The next prime is 688549733. The reversal of 688549723 is 327945886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 327945886 = 2 ⋅163972943.

It is a cyclic number.

It is not a de Polignac number, because 688549723 - 2¹⁷ = 688418651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688549733) 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, 56203 + ... + 67348.

It is an arithmetic number, because the mean of its divisors is an integer number (172169712).

Almost surely, 2^688549723 is an apocalyptic number.

688549723 is a deficient number, since it is larger than the sum of its proper divisors (129125).

688549723 is a wasteful number, since it uses less digits than its factorization.

688549723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129124.

The product of its digits is 2903040, while the sum is 52.

The square root of 688549723 is about 26240.2310012698. The cubic root of 688549723 is about 883.0360539294.

The spelling of 688549723 in words is "six hundred eighty-eight million, five hundred forty-nine thousand, seven hundred twenty-three".