21115666213006 has 16 divisors (see below), whose sum is σ = 31734908270208. Its totient is φ = 10537370379000.

The previous prime is 21115666212997. The next prime is 21115666213007. The reversal of 21115666213006 is 60031266651112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21115666213006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115666213007) 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, 4383121 + ... + 7838563.

It is an arithmetic number, because the mean of its divisors is an integer number (1983431766888).

Almost surely, 2^{21115666213006} is an apocalyptic number.

21115666213006 is a deficient number, since it is larger than the sum of its proper divisors (10619242057202).

21115666213006 is a wasteful number, since it uses less digits than its factorization.

21115666213006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3461367.

The product of its (nonzero) digits is 77760, while the sum is 40.

The spelling of 21115666213006 in words is "twenty-one trillion, one hundred fifteen billion, six hundred sixty-six million, two hundred thirteen thousand, six".