668071836 has 36 divisors (see below), whose sum is σ = 1689633400. Its totient is φ = 222572448.

The previous prime is 668071801. The next prime is 668071843. The reversal of 668071836 is 638170866.

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 668071791 and 668071800.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 87750 + ... + 95058.

Almost surely, 2^668071836 is an apocalyptic number.

It is an amenable number.

668071836 is an abundant number, since it is smaller than the sum of its proper divisors (1021561564).

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

668071836 is a wasteful number, since it uses less digits than its factorization.

668071836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9858 (or 9853 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 668071836 is about 25847.0856384235. The cubic root of 668071836 is about 874.1937982588.

The spelling of 668071836 in words is "six hundred sixty-eight million, seventy-one thousand, eight hundred thirty-six".