21211010000 has 100 divisors (see below), whose sum is σ = 51864901044. Its totient is φ = 8400000000.

The previous prime is 21211009969. The next prime is 21211010003. The reversal of 21211010000 is 1011212.

It can be written as a sum of positive squares in 10 ways, for example, as 13577842576 + 7633167424 = 116524^2 + 87368^2 .

It is a tau number, because it is divible by the number of its divisors (100).

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21211010000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211010003) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 999500 + ... + 1020500.

Almost surely, 2^21211010000 is an apocalyptic number.

21211010000 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 21211010000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25932450522).

21211010000 is an abundant number, since it is smaller than the sum of its proper divisors (30653891044).

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

21211010000 is a wasteful number, since it uses less digits than its factorization.

21211010000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21130 (or 21109 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21211010000 its reverse (1011212), we get a palindrome (21212021212).

The spelling of 21211010000 in words is "twenty-one billion, two hundred eleven million, ten thousand".