21021210210 has 288 divisors, whose sum is σ = 69477863616. Its totient is φ = 4031596800.

The previous prime is 21021210187. The next prime is 21021210211. The reversal of 21021210210 is 1201212012.

It is not an unprimeable number, because it can be changed into a prime (21021210211) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2307765 + ... + 2316855.

It is an arithmetic number, because the mean of its divisors is an integer number (241242582).

Almost surely, 2^21021210210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021210210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34738931808).

21021210210 is an abundant number, since it is smaller than the sum of its proper divisors (48456653406).

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

21021210210 is a wasteful number, since it uses less digits than its factorization.

21021210210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150 (or 9132 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21021210210 its reverse (1201212012), we get a palindrome (22222422222).

The spelling of 21021210210 in words is "twenty-one billion, twenty-one million, two hundred ten thousand, two hundred ten".