21520414244 has 24 divisors (see below), whose sum is σ = 43060194240. Its totient is φ = 9218884896.

The previous prime is 21520414243. The next prime is 21520414319. The reversal of 21520414244 is 44241402512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21520414243) 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, 109154 + ... + 234425.

It is an arithmetic number, because the mean of its divisors is an integer number (1794174760).

Almost surely, 2^21520414244 is an apocalyptic number.

It is an amenable number.

21520414244 is an abundant number, since it is smaller than the sum of its proper divisors (21539779996).

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

21520414244 is a wasteful number, since it uses less digits than its factorization.

21520414244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345827 (or 345825 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 29.

Adding to 21520414244 its reverse (44241402512), we get a palindrome (65761816756).

The spelling of 21520414244 in words is "twenty-one billion, five hundred twenty million, four hundred fourteen thousand, two hundred forty-four".