21615543213166 has 96 divisors (see below), whose sum is σ = 39397118584320. Its totient is φ = 8711532597312.

The previous prime is 21615543213163. The next prime is 21615543213179. The reversal of 21615543213166 is 66131234551612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21615543213163) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 618647725 + ... + 618682663.

It is an arithmetic number, because the mean of its divisors is an integer number (410386651920).

Almost surely, 2^{21615543213166} is an apocalyptic number.

21615543213166 is a deficient number, since it is larger than the sum of its proper divisors (17781575371154).

21615543213166 is a wasteful number, since it uses less digits than its factorization.

21615543213166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35886 (or 35867 counting only the distinct ones).

The product of its digits is 777600, while the sum is 46.

Adding to 21615543213166 its reverse (66131234551612), we get a palindrome (87746777764778).

The spelling of 21615543213166 in words is "twenty-one trillion, six hundred fifteen billion, five hundred forty-three million, two hundred thirteen thousand, one hundred sixty-six".