21076864166 has 4 divisors (see below), whose sum is σ = 31615296252. Its totient is φ = 10538432082.

The previous prime is 21076864157. The next prime is 21076864169. The reversal of 21076864166 is 66146867012.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21076864166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21076864169) 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 as a sum of consecutive naturals, namely, 5269216040 + ... + 5269216043.

It is an arithmetic number, because the mean of its divisors is an integer number (7903824063).

Almost surely, 2^21076864166 is an apocalyptic number.

21076864166 is a deficient number, since it is larger than the sum of its proper divisors (10538432086).

21076864166 is a wasteful number, since it uses less digits than its factorization.

21076864166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10538432085.

The product of its (nonzero) digits is 580608, while the sum is 47.

The spelling of 21076864166 in words is "twenty-one billion, seventy-six million, eight hundred sixty-four thousand, one hundred sixty-six".