684731407 has 4 divisors (see below), whose sum is σ = 684789336. Its totient is φ = 684673480.

The previous prime is 684731401. The next prime is 684731417. The reversal of 684731407 is 704137486.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 684731407 - 2⁷ = 684731279 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 684731407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684731401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4144 + ... + 37237.

It is an arithmetic number, because the mean of its divisors is an integer number (171197334).

Almost surely, 2^684731407 is an apocalyptic number.

684731407 is a deficient number, since it is larger than the sum of its proper divisors (57929).

684731407 is a wasteful number, since it uses less digits than its factorization.

684731407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57928.

The product of its (nonzero) digits is 112896, while the sum is 40.

The square root of 684731407 is about 26167.3729480053. The cubic root of 684731407 is about 881.4007508179.

The spelling of 684731407 in words is "six hundred eighty-four million, seven hundred thirty-one thousand, four hundred seven".