212121100 has 36 divisors (see below), whose sum is σ = 461704824. Its totient is φ = 84590080.

The previous prime is 212121067. The next prime is 212121113. The reversal of 212121100 is 1121212.

It is a super-3 number, since 3×212121100³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31644 + ... + 37756.

It is an arithmetic number, because the mean of its divisors is an integer number (12825134).

Almost surely, 2^212121100 is an apocalyptic number.

212121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212121100 is an abundant number, since it is smaller than the sum of its proper divisors (249583724).

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

212121100 is a wasteful number, since it uses less digits than its factorization.

212121100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6474 (or 6467 counting only the distinct ones).

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

The square root of 212121100 is about 14564.3777759299. The cubic root of 212121100 is about 596.3867098297.

Adding to 212121100 its reverse (1121212), we get a palindrome (213242312).

The spelling of 212121100 in words is "two hundred twelve million, one hundred twenty-one thousand, one hundred".