684139550 has 12 divisors (see below), whose sum is σ = 1272499656. Its totient is φ = 273655800.

The previous prime is 684139543. The next prime is 684139579. The reversal of 684139550 is 55931486.

It is a junction number, because it is equal to n+sod(n) for n = 684139498 and 684139507.

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 6841346 + ... + 6841445.

It is an arithmetic number, because the mean of its divisors is an integer number (106041638).

Almost surely, 2^684139550 is an apocalyptic number.

684139550 is a deficient number, since it is larger than the sum of its proper divisors (588360106).

684139550 is a wasteful number, since it uses less digits than its factorization.

684139550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13682803 (or 13682798 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 41.

The square root of 684139550 is about 26156.0614389858. The cubic root of 684139550 is about 881.1467273310.

The spelling of 684139550 in words is "six hundred eighty-four million, one hundred thirty-nine thousand, five hundred fifty".