21515414224144 has 20 divisors (see below), whose sum is σ = 41686734897180. Its totient is φ = 10757547153920.

The previous prime is 21515414224081. The next prime is 21515414224153. The reversal of 21515414224144 is 44142241451512.

It can be written as a sum of positive squares in 2 ways, for example, as 20739098160400 + 776316063744 = 4554020^2 + 881088^2 .

It is a super-2 number, since 2×21515414224144² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21515414224097 and 21515414224106.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8883949 + ... + 11043340.

It is an arithmetic number, because the mean of its divisors is an integer number (2084336744859).

Almost surely, 2^{21515414224144} is an apocalyptic number.

It is an amenable number.

21515414224144 is a deficient number, since it is larger than the sum of its proper divisors (20171320673036).

21515414224144 is a wasteful number, since it uses less digits than its factorization.

21515414224144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19994778 (or 19994772 counting only the distinct ones).

The product of its digits is 204800, while the sum is 40.

Adding to 21515414224144 its reverse (44142241451512), we get a palindrome (65657655675656).

The spelling of 21515414224144 in words is "twenty-one trillion, five hundred fifteen billion, four hundred fourteen million, two hundred twenty-four thousand, one hundred forty-four".