684691650 has 96 divisors (see below), whose sum is σ = 1898628480. Its totient is φ = 181431360.

The previous prime is 684691639. The next prime is 684691663. The reversal of 684691650 is 56196486.

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

It is a junction number, because it is equal to n+sod(n) for n = 684691596 and 684691605.

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, 223932 + ... + 226968.

It is an arithmetic number, because the mean of its divisors is an integer number (19777380).

Almost surely, 2^684691650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684691650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (949314240).

684691650 is an abundant number, since it is smaller than the sum of its proper divisors (1213936830).

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

684691650 is a wasteful number, since it uses less digits than its factorization.

684691650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3225 (or 3214 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 684691650 is about 26166.6132695846. The cubic root of 684691650 is about 881.3836918039.

The spelling of 684691650 in words is "six hundred eighty-four million, six hundred ninety-one thousand, six hundred fifty".