21166311669 has 8 divisors (see below), whose sum is σ = 29881851840. Its totient is φ = 13280822976.

The previous prime is 21166311659. The next prime is 21166311707. The reversal of 21166311669 is 96611366112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21166311669 - 2⁴ = 21166311653 is a prime.

It is a super-2 number, since 2×21166311669² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21166311669.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166311659) 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 7 ways as a sum of consecutive naturals, for example, 207512809 + ... + 207512910.

It is an arithmetic number, because the mean of its divisors is an integer number (3735231480).

Almost surely, 2^21166311669 is an apocalyptic number.

It is an amenable number.

21166311669 is a deficient number, since it is larger than the sum of its proper divisors (8715540171).

21166311669 is a wasteful number, since it uses less digits than its factorization.

21166311669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415025739.

The product of its digits is 69984, while the sum is 42.

The spelling of 21166311669 in words is "twenty-one billion, one hundred sixty-six million, three hundred eleven thousand, six hundred sixty-nine".