684799966 has 24 divisors (see below), whose sum is σ = 1054494504. Its totient is φ = 333487440.

The previous prime is 684799873. The next prime is 684799979. The reversal of 684799966 is 669997486.

It is a junction number, because it is equal to n+sod(n) for n = 684799898 and 684799907.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1035676 + ... + 1036336.

It is an arithmetic number, because the mean of its divisors is an integer number (43937271).

Almost surely, 2^684799966 is an apocalyptic number.

684799966 is a deficient number, since it is larger than the sum of its proper divisors (369694538).

684799966 is an equidigital number, since it uses as much as digits as its factorization.

684799966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 904 (or 825 counting only the distinct ones).

The product of its digits is 35271936, while the sum is 64.

The square root of 684799966 is about 26168.6829244423. The cubic root of 684799966 is about 881.4301667011.

The spelling of 684799966 in words is "six hundred eighty-four million, seven hundred ninety-nine thousand, nine hundred sixty-six".