689668660408 has 256 divisors, whose sum is σ = 1669906022400. Its totient is φ = 259810467840.

The previous prime is 689668660339. The next prime is 689668660409. The reversal of 689668660408 is 804066866986.

It is a happy number.

It is a super-2 number, since 2×689668660408² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689668660409) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 203380393 + ... + 203383783.

It is an arithmetic number, because the mean of its divisors is an integer number (6523070400).

Almost surely, 2^689668660408 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 689668660408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834953011200).

689668660408 is an abundant number, since it is smaller than the sum of its proper divisors (980237361992).

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

689668660408 is a wasteful number, since it uses less digits than its factorization.

689668660408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3622 (or 3618 counting only the distinct ones).

The product of its (nonzero) digits is 143327232, while the sum is 67.

The spelling of 689668660408 in words is "six hundred eighty-nine billion, six hundred sixty-eight million, six hundred sixty thousand, four hundred eight".