21164111889870 has 64 divisors (see below), whose sum is σ = 52433729740800. Its totient is φ = 5461565740800.

The previous prime is 21164111889853. The next prime is 21164111889917. The reversal of 21164111889870 is 7898811146112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21164111889870.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38647675 + ... + 39191465.

It is an arithmetic number, because the mean of its divisors is an integer number (819277027200).

Almost surely, 2^{21164111889870} is an apocalyptic number.

21164111889870 is an abundant number, since it is smaller than the sum of its proper divisors (31269617850930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21164111889870 is a wasteful number, since it uses less digits than its factorization.

21164111889870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585681.

The product of its (nonzero) digits is 1548288, while the sum is 57.

The spelling of 21164111889870 in words is "twenty-one trillion, one hundred sixty-four billion, one hundred eleven million, eight hundred eighty-nine thousand, eight hundred seventy".