21211212211000 has 256 divisors, whose sum is σ = 57350861568000. Its totient is φ = 7192556467200.

The previous prime is 21211212210997. The next prime is 21211212211009. The reversal of 21211212211000 is 11221211212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211212211009) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 255857556 + ... + 255940444.

It is an arithmetic number, because the mean of its divisors is an integer number (224026803000).

Almost surely, 2^{21211212211000} is an apocalyptic number.

21211212211000 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 21211212211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28675430784000).

21211212211000 is an abundant number, since it is smaller than the sum of its proper divisors (36139649357000).

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

21211212211000 is a wasteful number, since it uses less digits than its factorization.

21211212211000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83319 (or 83305 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21211212211000 its reverse (11221211212), we get a palindrome (21222433422212).

The spelling of 21211212211000 in words is "twenty-one trillion, two hundred eleven billion, two hundred twelve million, two hundred eleven thousand".