684638031 has 32 divisors (see below), whose sum is σ = 1139521536. Its totient is φ = 355212000.

The previous prime is 684638011. The next prime is 684638041. The reversal of 684638031 is 130836486.

It is not a de Polignac number, because 684638031 - 2⁵ = 684637999 is a prime.

It is a super-2 number, since 2×684638031² = 937458466983113922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684638011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 269236 + ... + 271766.

It is an arithmetic number, because the mean of its divisors is an integer number (35610048).

Almost surely, 2^684638031 is an apocalyptic number.

684638031 is a deficient number, since it is larger than the sum of its proper divisors (454883505).

684638031 is a wasteful number, since it uses less digits than its factorization.

684638031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3723.

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 684638031 is about 26165.5886805552. The cubic root of 684638031 is about 881.3606838091.

The spelling of 684638031 in words is "six hundred eighty-four million, six hundred thirty-eight thousand, thirty-one".