21201110110208 has 208 divisors, whose sum is σ = 50590417453056. Its totient is φ = 8685987594240.

The previous prime is 21201110110207. The next prime is 21201110110211. The reversal of 21201110110208 is 80201101110212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21201110110208.

It is not an unprimeable number, because it can be changed into a prime (21201110110207) 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, 1233833585 + ... + 1233850767.

It is an arithmetic number, because the mean of its divisors is an integer number (243223160832).

Almost surely, 2^{21201110110208} is an apocalyptic number.

21201110110208 is a gapful number since it is divisible by the number (28) 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 21201110110208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25295208726528).

21201110110208 is an abundant number, since it is smaller than the sum of its proper divisors (29389307342848).

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

21201110110208 is a wasteful number, since it uses less digits than its factorization.

21201110110208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19108 (or 19086 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 20.

The spelling of 21201110110208 in words is "twenty-one trillion, two hundred one billion, one hundred ten million, one hundred ten thousand, two hundred eight".