21012211000 has 256 divisors, whose sum is σ = 55935360000. Its totient is φ = 7318080000.

The previous prime is 21012210997. The next prime is 21012211007. The reversal of 21012211000 is 11221012.

It is a super-2 number, since 2×21012211000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012211007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 63480835 + ... + 63481165.

It is an arithmetic number, because the mean of its divisors is an integer number (218497500).

Almost surely, 2^21012211000 is an apocalyptic number.

21012211000 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 21012211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27967680000).

21012211000 is an abundant number, since it is smaller than the sum of its proper divisors (34923149000).

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

21012211000 is a wasteful number, since it uses less digits than its factorization.

21012211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21012211000 its reverse (11221012), we get a palindrome (21023432012).

It can be divided in two parts, 210122 and 11000, that added together give a palindrome (221122).

The spelling of 21012211000 in words is "twenty-one billion, twelve million, two hundred eleven thousand".