689557728 has 96 divisors (see below), whose sum is σ = 1914071040. Its totient is φ = 216760320.

The previous prime is 689557717. The next prime is 689557783. The reversal of 689557728 is 827755986.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 468033 + ... + 469503.

It is an arithmetic number, because the mean of its divisors is an integer number (19938240).

Almost surely, 2^689557728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 689557728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (957035520).

689557728 is an abundant number, since it is smaller than the sum of its proper divisors (1224513312).

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

689557728 is a wasteful number, since it uses less digits than its factorization.

689557728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760 (or 1752 counting only the distinct ones).

The product of its digits is 8467200, while the sum is 57.

The square root of 689557728 is about 26259.4312200398. The cubic root of 689557728 is about 883.4667518264.

The spelling of 689557728 in words is "six hundred eighty-nine million, five hundred fifty-seven thousand, seven hundred twenty-eight".