21821144070 has 128 divisors (see below), whose sum is σ = 60634137600. Its totient is φ = 4967137280.

The previous prime is 21821144069. The next prime is 21821144071. The reversal of 21821144070 is 7044112812.

It is an interprime number because it is at equal distance from previous prime (21821144069) and next prime (21821144071).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21821144071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2514559 + ... + 2523221.

It is an arithmetic number, because the mean of its divisors is an integer number (473704200).

Almost surely, 2^21821144070 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21821144070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30317068800).

21821144070 is an abundant number, since it is smaller than the sum of its proper divisors (38812993530).

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

21821144070 is a wasteful number, since it uses less digits than its factorization.

21821144070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9150.

The product of its (nonzero) digits is 3584, while the sum is 30.

Adding to 21821144070 its reverse (7044112812), we get a palindrome (28865256882).

The spelling of 21821144070 in words is "twenty-one billion, eight hundred twenty-one million, one hundred forty-four thousand, seventy".