212121000 has 576 divisors, whose sum is σ = 922456080. Its totient is φ = 43545600.

The previous prime is 212120983. The next prime is 212121023. The reversal of 212121000 is 121212.

212121000 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 9400356 + 202720644 = 3066^2 + 14238^2 .

It is a super-3 number, since 3×212121000³ (a number of 26 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 5732982 + ... + 5733018.

Almost surely, 2^212121000 is an apocalyptic number.

212121000 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 212121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (461228040).

212121000 is an abundant number, since it is smaller than the sum of its proper divisors (710335080).

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

212121000 is a wasteful number, since it uses less digits than its factorization.

212121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 212121000 is about 14564.3743428957. The cubic root of 212121000 is about 596.3866161117.

Adding to 212121000 its reverse (121212), we get a palindrome (212242212).

The spelling of 212121000 in words is "two hundred twelve million, one hundred twenty-one thousand".