688420980 has 144 divisors (see below), whose sum is σ = 2282926464. Its totient is φ = 166890240.

The previous prime is 688420969. The next prime is 688421023. The reversal of 688420980 is 89024886.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 154585 + ... + 158975.

It is an arithmetic number, because the mean of its divisors is an integer number (15853656).

Almost surely, 2^688420980 is an apocalyptic number.

688420980 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 688420980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1141463232).

688420980 is an abundant number, since it is smaller than the sum of its proper divisors (1594505484).

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

688420980 is a wasteful number, since it uses less digits than its factorization.

688420980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4486 (or 4481 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 688420980 is about 26237.7777260194. Note that the first 4 decimals coincide. The cubic root of 688420980 is about 882.9810146717.

The spelling of 688420980 in words is "six hundred eighty-eight million, four hundred twenty thousand, nine hundred eighty".