666101020 has 24 divisors (see below), whose sum is σ = 1506413664. Its totient is φ = 245944896.

The previous prime is 666101011. The next prime is 666101041. The reversal of 666101020 is 20101666.

It is a junction number, because it is equal to n+sod(n) for n = 666100982 and 666101000.

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 7 ways as a sum of consecutive naturals, for example, 1280704 + ... + 1281223.

It is an arithmetic number, because the mean of its divisors is an integer number (62767236).

Almost surely, 2^666101020 is an apocalyptic number.

It is an amenable number.

666101020 is an abundant number, since it is smaller than the sum of its proper divisors (840312644).

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

666101020 is a wasteful number, since it uses less digits than its factorization.

666101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2561949 (or 2561947 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 666101020 is about 25808.9329496591. The cubic root of 666101020 is about 873.3333258875. Note that the first 4 decimals are identical.

Adding to 666101020 its reverse (20101666), we get a palindrome (686202686).

The spelling of 666101020 in words is "six hundred sixty-six million, one hundred one thousand, twenty".