21894104121 has 12 divisors (see below), whose sum is σ = 29547002352. Its totient is φ = 14418675328.

The previous prime is 21894104119. The next prime is 21894104137. The reversal of 21894104121 is 12140149812.

It is not a de Polignac number, because 21894104121 - 2¹ = 21894104119 is a prime.

It is a super-2 number, since 2×21894104121² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21894104191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2330185 + ... + 2339561.

It is an arithmetic number, because the mean of its divisors is an integer number (2462250196).

Almost surely, 2^21894104121 is an apocalyptic number.

It is an amenable number.

21894104121 is a deficient number, since it is larger than the sum of its proper divisors (7652898231).

21894104121 is an frugal number, since it uses more digits than its factorization.

21894104121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18840 (or 9463 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The spelling of 21894104121 in words is "twenty-one billion, eight hundred ninety-four million, one hundred four thousand, one hundred twenty-one".