6661566021212 has 24 divisors (see below), whose sum is σ = 11666688324480. Its totient is φ = 3328226841600.

The previous prime is 6661566021193. The next prime is 6661566021217. The reversal of 6661566021212 is 2121206651666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661566021217) 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, 99988712 + ... + 100055312.

It is an arithmetic number, because the mean of its divisors is an integer number (486112013520).

Almost surely, 2^{6661566021212} is an apocalyptic number.

It is an amenable number.

6661566021212 is a deficient number, since it is larger than the sum of its proper divisors (5005122303268).

6661566021212 is a wasteful number, since it uses less digits than its factorization.

6661566021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85421 (or 85419 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 6661566021212 in words is "six trillion, six hundred sixty-one billion, five hundred sixty-six million, twenty-one thousand, two hundred twelve".