21162021166 has 48 divisors (see below), whose sum is σ = 38328368400. Its totient is φ = 8639032320.

The previous prime is 21162021163. The next prime is 21162021187. The reversal of 21162021166 is 66112026112.

It is a super-2 number, since 2×21162021166² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21162021163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 364510 + ... + 418558.

It is an arithmetic number, because the mean of its divisors is an integer number (798507675).

Almost surely, 2^21162021166 is an apocalyptic number.

21162021166 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21162021166 is a deficient number, since it is larger than the sum of its proper divisors (17166347234).

21162021166 is a wasteful number, since it uses less digits than its factorization.

21162021166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54149 (or 54112 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

Adding to 21162021166 its reverse (66112026112), we get a palindrome (87274047278).

The spelling of 21162021166 in words is "twenty-one billion, one hundred sixty-two million, twenty-one thousand, one hundred sixty-six".