21821248845 has 48 divisors (see below), whose sum is σ = 41360402304. Its totient is φ = 10554768000.

The previous prime is 21821248837. The next prime is 21821248847. The reversal of 21821248845 is 54884212812.

It is a happy number.

It is not a de Polignac number, because 21821248845 - 2³ = 21821248837 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21821248845.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21821248847) 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 47 ways as a sum of consecutive naturals, for example, 156040 + ... + 260750.

It is an arithmetic number, because the mean of its divisors is an integer number (861675048).

Almost surely, 2^21821248845 is an apocalyptic number.

It is an amenable number.

21821248845 is a deficient number, since it is larger than the sum of its proper divisors (19539153459).

21821248845 is a wasteful number, since it uses less digits than its factorization.

21821248845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105154 (or 105151 counting only the distinct ones).

The product of its digits is 327680, while the sum is 45.

The spelling of 21821248845 in words is "twenty-one billion, eight hundred twenty-one million, two hundred forty-eight thousand, eight hundred forty-five".