21112120221210 has 192 divisors, whose sum is σ = 55585844364960. Its totient is φ = 5558973235200.

The previous prime is 21112120221151. The next prime is 21112120221233. The reversal of 21112120221210 is 1212202121112.

21112120221210 is a `hidden beast` number, since 2 + 1 + 112 + 120 + 221 + 210 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 1729506421449 + 19382613799761 = 1315107^2 + 4402569^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11722442310 + ... + 11722444110.

Almost surely, 2^{21112120221210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21112120221210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27792922182480).

21112120221210 is an abundant number, since it is smaller than the sum of its proper divisors (34473724143750).

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

21112120221210 is a wasteful number, since it uses less digits than its factorization.

21112120221210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4273 (or 4270 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21112120221210 its reverse (1212202121112), we get a palindrome (22324322342322).

The spelling of 21112120221210 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty million, two hundred twenty-one thousand, two hundred ten".