688409280 has 392 divisors, whose sum is σ = 2658508272. Its totient is φ = 168708096.

The previous prime is 688409269. The next prime is 688409327. The reversal of 688409280 is 82904886.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 3032527 + ... + 3032753.

Almost surely, 2^688409280 is an apocalyptic number.

688409280 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 688409280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1329254136).

688409280 is an abundant number, since it is smaller than the sum of its proper divisors (1970098992).

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

688409280 is a wasteful number, since it uses less digits than its factorization.

688409280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 250 counting only the distinct ones).

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

The square root of 688409280 is about 26237.5547641163. The cubic root of 688409280 is about 882.9760124339.

The spelling of 688409280 in words is "six hundred eighty-eight million, four hundred nine thousand, two hundred eighty".