689631840 has 192 divisors, whose sum is σ = 2454217920. Its totient is φ = 180817920.

The previous prime is 689631827. The next prime is 689631841. The reversal of 689631840 is 48136986.

689631840 is a `hidden beast` number, since 6 + 8 + 9 + 631 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689631841) 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 31 ways as a sum of consecutive naturals, for example, 262212 + ... + 264828.

It is an arithmetic number, because the mean of its divisors is an integer number (12782385).

Almost surely, 2^689631840 is an apocalyptic number.

689631840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 689631840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1227108960).

689631840 is an abundant number, since it is smaller than the sum of its proper divisors (1764586080).

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

689631840 is a wasteful number, since it uses less digits than its factorization.

689631840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2702 (or 2688 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 689631840 is about 26260.8423322634. The cubic root of 689631840 is about 883.4984016505.

The spelling of 689631840 in words is "six hundred eighty-nine million, six hundred thirty-one thousand, eight hundred forty".