21520444422 has 16 divisors (see below), whose sum is σ = 43073936640. Its totient is φ = 7167973512.

The previous prime is 21520444417. The next prime is 21520444427. The reversal of 21520444422 is 22444402512.

It is an interprime number because it is at equal distance from previous prime (21520444417) and next prime (21520444427).

It is a self number, because there is not a number n which added to its sum of digits gives 21520444422.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520444427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1368522 + ... + 1384157.

It is an arithmetic number, because the mean of its divisors is an integer number (2692121040).

Almost surely, 2^21520444422 is an apocalyptic number.

21520444422 is an abundant number, since it is smaller than the sum of its proper divisors (21553492218).

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

21520444422 is a wasteful number, since it uses less digits than its factorization.

21520444422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2753987.

The product of its (nonzero) digits is 20480, while the sum is 30.

Adding to 21520444422 its reverse (22444402512), we get a palindrome (43964846934).

The spelling of 21520444422 in words is "twenty-one billion, five hundred twenty million, four hundred forty-four thousand, four hundred twenty-two".