684202644 has 18 divisors (see below), whose sum is σ = 1729512330. Its totient is φ = 228067536.

The previous prime is 684202639. The next prime is 684202661. The reversal of 684202644 is 446202486.

It is a happy number.

684202644 is a `hidden beast` number, since 6 + 8 + 4 + 2 + 0 + 2 + 644 = 666.

It can be written as a sum of positive squares in only one way, i.e., 583802244 + 100400400 = 24162^2 + 10020^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 19005629 = 684202644 / (6 + 8 + 4 + 2 + 0 + 2 + 6 + 4 + 4).

It is a junction number, because it is equal to n+sod(n) for n = 684202599 and 684202608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9502779 + ... + 9502850.

Almost surely, 2^684202644 is an apocalyptic number.

It is an amenable number.

684202644 is an abundant number, since it is smaller than the sum of its proper divisors (1045309686).

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

684202644 is a wasteful number, since it uses less digits than its factorization.

684202644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19005639 (or 19005634 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 36.

The square root of 684202644 is about 26157.2675178429. The cubic root of 684202644 is about 881.1738140868.

The spelling of 684202644 in words is "six hundred eighty-four million, two hundred two thousand, six hundred forty-four".