667819212 has 12 divisors (see below), whose sum is σ = 1558244856. Its totient is φ = 222606400.

The previous prime is 667819199. The next prime is 667819219. The reversal of 667819212 is 212918766.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (667819219) 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, 27825789 + ... + 27825812.

It is an arithmetic number, because the mean of its divisors is an integer number (129853738).

Almost surely, 2^667819212 is an apocalyptic number.

It is an amenable number.

667819212 is an abundant number, since it is smaller than the sum of its proper divisors (890425644).

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

667819212 is a wasteful number, since it uses less digits than its factorization.

667819212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55651608 (or 55651606 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 667819212 is about 25842.1982811060. The cubic root of 667819212 is about 874.0835954511.

It can be divided in two parts, 6678192 and 12, that multiplied together give a square (80138304 = 8952²).

The spelling of 667819212 in words is "six hundred sixty-seven million, eight hundred nineteen thousand, two hundred twelve".