21854841138 has 48 divisors (see below), whose sum is σ = 51084249216. Its totient is φ = 6712748640.

The previous prime is 21854841133. The next prime is 21854841149. The reversal of 21854841138 is 83114845812.

It is a junction number, because it is equal to n+sod(n) for n = 21854841093 and 21854841102.

It is not an unprimeable number, because it can be changed into a prime (21854841133) 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, 51831 + ... + 215397.

It is an arithmetic number, because the mean of its divisors is an integer number (1064255192).

Almost surely, 2^21854841138 is an apocalyptic number.

21854841138 is an abundant number, since it is smaller than the sum of its proper divisors (29229408078).

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

21854841138 is a wasteful number, since it uses less digits than its factorization.

21854841138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164159 (or 164156 counting only the distinct ones).

The product of its digits is 245760, while the sum is 45.

The spelling of 21854841138 in words is "twenty-one billion, eight hundred fifty-four million, eight hundred forty-one thousand, one hundred thirty-eight".