688644450 has 96 divisors (see below), whose sum is σ = 2043619200. Its totient is φ = 169508160.

The previous prime is 688644413. The next prime is 688644461. The reversal of 688644450 is 54446886.

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 = 688644396 and 688644405.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 2070 + ... + 37169.

It is an arithmetic number, because the mean of its divisors is an integer number (21287700).

Almost surely, 2^688644450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688644450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1021809600).

688644450 is an abundant number, since it is smaller than the sum of its proper divisors (1354974750).

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

688644450 is a wasteful number, since it uses less digits than its factorization.

688644450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39273 (or 39262 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 45.

The square root of 688644450 is about 26242.0359347365. The cubic root of 688644450 is about 883.0765465367.

The spelling of 688644450 in words is "six hundred eighty-eight million, six hundred forty-four thousand, four hundred fifty".