21221144160 has 96 divisors (see below), whose sum is σ = 66890486880. Its totient is φ = 5655257088.

The previous prime is 21221144107. The next prime is 21221144167. The reversal of 21221144160 is 6144112212.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21221144160.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221144167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 760536 + ... + 787944.

It is an arithmetic number, because the mean of its divisors is an integer number (696775905).

Almost surely, 2^21221144160 is an apocalyptic number.

21221144160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221144160 is an abundant number, since it is smaller than the sum of its proper divisors (45669342720).

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

21221144160 is a wasteful number, since it uses less digits than its factorization.

21221144160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29040 (or 29032 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

Adding to 21221144160 its reverse (6144112212), we get a palindrome (27365256372).

The spelling of 21221144160 in words is "twenty-one billion, two hundred twenty-one million, one hundred forty-four thousand, one hundred sixty".