21220224144 has 80 divisors (see below), whose sum is σ = 63712112640. Its totient is φ = 5960154240.

The previous prime is 21220224107. The next prime is 21220224161. The reversal of 21220224144 is 44142202212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 515392 + ... + 555039.

It is an arithmetic number, because the mean of its divisors is an integer number (796401408).

Almost surely, 2^21220224144 is an apocalyptic number.

21220224144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21220224144 is an abundant number, since it is smaller than the sum of its proper divisors (42491888496).

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

21220224144 is a wasteful number, since it uses less digits than its factorization.

21220224144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070508 (or 1070502 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

Adding to 21220224144 its reverse (44142202212), we get a palindrome (65362426356).

The spelling of 21220224144 in words is "twenty-one billion, two hundred twenty million, two hundred twenty-four thousand, one hundred forty-four".