684393012 has 18 divisors (see below), whose sum is σ = 1729993538. Its totient is φ = 228130992.

The previous prime is 684392993. The next prime is 684393013. The reversal of 684393012 is 210393486.

It can be written as a sum of positive squares in only one way, i.e., 679957776 + 4435236 = 26076^2 + 2106^2 .

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

It is a super-3 number, since 3×684393012³ (a number of 27 digits) contains 333 as substring.

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: 19010917 = 684393012 / (6 + 8 + 4 + 3 + 9 + 3 + 0 + 1 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684393013) by changing a digit.

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, 9505423 + ... + 9505494.

Almost surely, 2^684393012 is an apocalyptic number.

It is an amenable number.

684393012 is an abundant number, since it is smaller than the sum of its proper divisors (1045600526).

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

684393012 is a wasteful number, since it uses less digits than its factorization.

684393012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19010927 (or 19010922 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 684393012 is about 26160.9061769657. The cubic root of 684393012 is about 881.2555304919.

The spelling of 684393012 in words is "six hundred eighty-four million, three hundred ninety-three thousand, twelve".