21138775748189 has 24 divisors (see below), whose sum is σ = 24110368199904. Its totient is φ = 18378750852000.

The previous prime is 21138775748107. The next prime is 21138775748239. The reversal of 21138775748189 is 98184757783112.

It is not a de Polignac number, because 21138775748189 - 2²⁰ = 21138774699613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21138775708189) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38487674 + ... + 39033044.

It is an arithmetic number, because the mean of its divisors is an integer number (1004598674996).

Almost surely, 2^{21138775748189} is an apocalyptic number.

It is an amenable number.

21138775748189 is a deficient number, since it is larger than the sum of its proper divisors (2971592451715).

21138775748189 is a wasteful number, since it uses less digits than its factorization.

21138775748189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552089 (or 552066 counting only the distinct ones).

The product of its digits is 189665280, while the sum is 71.

The spelling of 21138775748189 in words is "twenty-one trillion, one hundred thirty-eight billion, seven hundred seventy-five million, seven hundred forty-eight thousand, one hundred eighty-nine".