21102201216 has 128 divisors (see below), whose sum is σ = 62437260000. Its totient is φ = 7016398848.

The previous prime is 21102201187. The next prime is 21102201217. The reversal of 21102201216 is 61210220112.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102201217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1406040 + ... + 1420968.

Almost surely, 2^21102201216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21102201216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31218630000).

21102201216 is an abundant number, since it is smaller than the sum of its proper divisors (41335058784).

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

21102201216 is a wasteful number, since it uses less digits than its factorization.

21102201216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15361 (or 15343 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21102201216 its reverse (61210220112), we get a palindrome (82312421328).

The spelling of 21102201216 in words is "twenty-one billion, one hundred two million, two hundred one thousand, two hundred sixteen".