21454144520 has 32 divisors (see below), whose sum is σ = 49298889600. Its totient is φ = 8399068608.

The previous prime is 21454144451. The next prime is 21454144531. The reversal of 21454144520 is 2544145412.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5704010 + ... + 5707769.

It is an arithmetic number, because the mean of its divisors is an integer number (1540590300).

Almost surely, 2^21454144520 is an apocalyptic number.

21454144520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21454144520 is an abundant number, since it is smaller than the sum of its proper divisors (27844745080).

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

21454144520 is a wasteful number, since it uses less digits than its factorization.

21454144520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11411837 (or 11411833 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 32.

Adding to 21454144520 its reverse (2544145412), we get a palindrome (23998289932).

The spelling of 21454144520 in words is "twenty-one billion, four hundred fifty-four million, one hundred forty-four thousand, five hundred twenty".