684378637 has 8 divisors (see below), whose sum is σ = 689912600. Its totient is φ = 678867264.

The previous prime is 684378631. The next prime is 684378641. The reversal of 684378637 is 736873486.

It can be written as a sum of positive squares in 4 ways, for example, as 129823236 + 554555401 = 11394^2 + 23549^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 684378637 - 2⁷ = 684378509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684378631) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 58039 + ... + 68827.

It is an arithmetic number, because the mean of its divisors is an integer number (86239075).

Almost surely, 2^684378637 is an apocalyptic number.

It is an amenable number.

684378637 is a deficient number, since it is larger than the sum of its proper divisors (5533963).

684378637 is a wasteful number, since it uses less digits than its factorization.

684378637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11295.

The product of its digits is 4064256, while the sum is 52.

The square root of 684378637 is about 26160.6314335109. The cubic root of 684378637 is about 881.2493604811.

The spelling of 684378637 in words is "six hundred eighty-four million, three hundred seventy-eight thousand, six hundred thirty-seven".