212121110100 has 72 divisors (see below), whose sum is σ = 614738813920. Its totient is φ = 56473303680.

The previous prime is 212121110093. The next prime is 212121110101. The reversal of 212121110100 is 1011121212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121110101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 392830 + ... + 760629.

Almost surely, 2^212121110100 is an apocalyptic number.

212121110100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212121110100 is an abundant number, since it is smaller than the sum of its proper divisors (402617703820).

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

212121110100 is a wasteful number, since it uses less digits than its factorization.

212121110100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1154089 (or 1154082 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 212121110100 its reverse (1011121212), we get a palindrome (213132231312).

The spelling of 212121110100 in words is "two hundred twelve billion, one hundred twenty-one million, one hundred ten thousand, one hundred".