21201211120 has 80 divisors (see below), whose sum is σ = 50054796288. Its totient is φ = 8350357760.

The previous prime is 21201211111. The next prime is 21201211133. The reversal of 21201211120 is 2111210212.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 21201211120.

It is a congruent number.

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, 1422105 + ... + 1436935.

Almost surely, 2^21201211120 is an apocalyptic number.

21201211120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201211120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25027398144).

21201211120 is an abundant number, since it is smaller than the sum of its proper divisors (28853585168).

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

21201211120 is a wasteful number, since it uses less digits than its factorization.

21201211120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15118 (or 15112 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21201211120 its reverse (2111210212), we get a palindrome (23312421332).

The spelling of 21201211120 in words is "twenty-one billion, two hundred one million, two hundred eleven thousand, one hundred twenty".