212121001000 has 64 divisors (see below), whose sum is σ = 500756003280. Its totient is φ = 84097484800.

The previous prime is 212121000979. The next prime is 212121001007. The reversal of 212121001000 is 100121212.

It can be written as a sum of positive squares in 8 ways, for example, as 3368873764 + 208752127236 = 58042^2 + 456894^2 .

It is a super-3 number, since 3×212121001000³ (a number of 35 digits) contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (212121001007) 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 15 ways as a sum of consecutive naturals, for example, 825589 + ... + 1051588.

Almost surely, 2^212121001000 is an apocalyptic number.

212121001000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212121001000 is an abundant number, since it is smaller than the sum of its proper divisors (288635002280).

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

212121001000 is a wasteful number, since it uses less digits than its factorization.

212121001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1877311 (or 1877297 counting only the distinct ones).

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

Adding to 212121001000 its reverse (100121212), we get a palindrome (212221122212).

The spelling of 212121001000 in words is "two hundred twelve billion, one hundred twenty-one million, one thousand".