21211211010 has 96 divisors (see below), whose sum is σ = 56923839936. Its totient is φ = 5016563200.

The previous prime is 21211210973. The next prime is 21211211017. The reversal of 21211211010 is 1011211212.

It is not an unprimeable number, because it can be changed into a prime (21211211017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 535612 + ... + 573848.

It is an arithmetic number, because the mean of its divisors is an integer number (592956666).

Almost surely, 2^21211211010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211211010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28461919968).

21211211010 is an abundant number, since it is smaller than the sum of its proper divisors (35712628926).

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

21211211010 is a wasteful number, since it uses less digits than its factorization.

21211211010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38340 (or 38299 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21211211010 its reverse (1011211212), we get a palindrome (22222422222).

It can be divided in two parts, 21211 and 211010, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 21211211010 in words is "twenty-one billion, two hundred eleven million, two hundred eleven thousand, ten".