206664642020 has 12 divisors (see below), whose sum is σ = 433995748284. Its totient is φ = 82665856800.

The previous prime is 206664642017. The next prime is 206664642029. The reversal of 206664642020 is 20246466602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 51108549184 + 155556092836 = 226072^2 + 394406^2 .

It is a super-2 number, since 2×206664642020² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (206664642029) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5166616031 + ... + 5166616070.

It is an arithmetic number, because the mean of its divisors is an integer number (36166312357).

Almost surely, 2^206664642020 is an apocalyptic number.

206664642020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206664642020 is an abundant number, since it is smaller than the sum of its proper divisors (227331106264).

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

206664642020 is a wasteful number, since it uses less digits than its factorization.

206664642020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10333232110 (or 10333232108 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 38.

The spelling of 206664642020 in words is "two hundred six billion, six hundred sixty-four million, six hundred forty-two thousand, twenty".