21221211120 has 40 divisors (see below), whose sum is σ = 65785755216. Its totient is φ = 5658989568.

The previous prime is 21221211113. The next prime is 21221211149. The reversal of 21221211120 is 2111212212.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×21221211120² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21221211120.

It is a congruent number.

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, 44210617 + ... + 44211096.

Almost surely, 2^21221211120 is an apocalyptic number.

21221211120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221211120 is an abundant number, since it is smaller than the sum of its proper divisors (44564544096).

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

21221211120 is a wasteful number, since it uses less digits than its factorization.

21221211120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88421729 (or 88421723 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221211120 its reverse (2111212212), we get a palindrome (23332423332).

The spelling of 21221211120 in words is "twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, one hundred twenty".