689724138 has 16 divisors (see below), whose sum is σ = 1439424576. Its totient is φ = 219912000.

The previous prime is 689724137. The next prime is 689724143. The reversal of 689724138 is 831427986.

689724138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (689724137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2498863 + ... + 2499138.

It is an arithmetic number, because the mean of its divisors is an integer number (89964036).

Almost surely, 2^689724138 is an apocalyptic number.

689724138 is an abundant number, since it is smaller than the sum of its proper divisors (749700438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

689724138 is a wasteful number, since it uses less digits than its factorization.

689724138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4998029.

The product of its digits is 580608, while the sum is 48.

The square root of 689724138 is about 26262.5996047611. The cubic root of 689724138 is about 883.5378147079.

The spelling of 689724138 in words is "six hundred eighty-nine million, seven hundred twenty-four thousand, one hundred thirty-eight".