688813650 has 288 divisors, whose sum is σ = 2360741760. Its totient is φ = 140175360.

The previous prime is 688813639. The next prime is 688813663. The reversal of 688813650 is 56318886.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 688813596 and 688813605.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1017112 + ... + 1017788.

It is an arithmetic number, because the mean of its divisors is an integer number (8197020).

Almost surely, 2^688813650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688813650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1180370880).

688813650 is an abundant number, since it is smaller than the sum of its proper divisors (1671928110).

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

688813650 is a wasteful number, since it uses less digits than its factorization.

688813650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738 (or 730 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 688813650 is about 26245.2595719684. The cubic root of 688813650 is about 883.1488646084.

The spelling of 688813650 in words is "six hundred eighty-eight million, eight hundred thirteen thousand, six hundred fifty".