6686221906 has 16 divisors (see below), whose sum is σ = 12343794624. Its totient is φ = 2645098704.

The previous prime is 6686221901. The next prime is 6686221939. The reversal of 6686221906 is 6091226866.

It is not an unprimeable number, because it can be changed into a prime (6686221901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18368560 + ... + 18368923.

It is an arithmetic number, because the mean of its divisors is an integer number (771487164).

Almost surely, 2^6686221906 is an apocalyptic number.

6686221906 is a deficient number, since it is larger than the sum of its proper divisors (5657572718).

6686221906 is a wasteful number, since it uses less digits than its factorization.

6686221906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36737505.

The product of its (nonzero) digits is 373248, while the sum is 46.

The square root of 6686221906 is about 81769.3213008400. The cubic root of 6686221906 is about 1883.9104798694.

The spelling of 6686221906 in words is "six billion, six hundred eighty-six million, two hundred twenty-one thousand, nine hundred six".