212121211000 has 128 divisors (see below), whose sum is σ = 507858024960. Its totient is φ = 82897152000.

The previous prime is 212121210991. The next prime is 212121211009. The reversal of 212121211000 is 112121212.

It is an interprime number because it is at equal distance from previous prime (212121210991) and next prime (212121211009).

It is a super-2 number, since 2×212121211000² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121211009) 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 31 ways as a sum of consecutive naturals, for example, 12764697 + ... + 12781303.

It is an arithmetic number, because the mean of its divisors is an integer number (3967640820).

Almost surely, 2^212121211000 is an apocalyptic number.

212121211000 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 212121211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253929012480).

212121211000 is an abundant number, since it is smaller than the sum of its proper divisors (295736813960).

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

212121211000 is a wasteful number, since it uses less digits than its factorization.

212121211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16922 (or 16908 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 212121211000 its reverse (112121212), we get a palindrome (212233332212).

The spelling of 212121211000 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred eleven thousand".