21010312166 has 16 divisors (see below), whose sum is σ = 31593120000. Its totient is φ = 10479292488.

The previous prime is 21010312151. The next prime is 21010312171. The reversal of 21010312166 is 66121301012.

It is a super-2 number, since 2×21010312166² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3309191 + ... + 3315533.

It is an arithmetic number, because the mean of its divisors is an integer number (1974570000).

Almost surely, 2^21010312166 is an apocalyptic number.

21010312166 is a deficient number, since it is larger than the sum of its proper divisors (10582807834).

21010312166 is a wasteful number, since it uses less digits than its factorization.

21010312166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10163.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21010312166 its reverse (66121301012), we get a palindrome (87131613178).

The spelling of 21010312166 in words is "twenty-one billion, ten million, three hundred twelve thousand, one hundred sixty-six".