21020020212210 has 256 divisors, whose sum is σ = 54494796238848. Its totient is φ = 5175741542400.

The previous prime is 21020020212199. The next prime is 21020020212293. The reversal of 21020020212210 is 1221202002012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21020020212210.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2836323405 + ... + 2836330815.

It is an arithmetic number, because the mean of its divisors is an integer number (212870297808).

Almost surely, 2^{21020020212210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020020212210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27247398119424).

21020020212210 is an abundant number, since it is smaller than the sum of its proper divisors (33474776026638).

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

21020020212210 is a wasteful number, since it uses less digits than its factorization.

21020020212210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8529.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020020212210 its reverse (1221202002012), we get a palindrome (22241222214222).

The spelling of 21020020212210 in words is "twenty-one trillion, twenty billion, twenty million, two hundred twelve thousand, two hundred ten".