212100021109 has 4 divisors (see below), whose sum is σ = 214200021420. Its totient is φ = 210000020800.

The previous prime is 212100021097. The next prime is 212100021137. The reversal of 212100021109 is 901120001212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 103185500625 + 108914520484 = 321225^2 + 330022^2 .

It is a cyclic number.

It is not a de Polignac number, because 212100021109 - 2²⁷ = 211965803381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212100021149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1050000004 + ... + 1050000205.

It is an arithmetic number, because the mean of its divisors is an integer number (53550005355).

Almost surely, 2^212100021109 is an apocalyptic number.

It is an amenable number.

212100021109 is a deficient number, since it is larger than the sum of its proper divisors (2100000311).

212100021109 is a wasteful number, since it uses less digits than its factorization.

212100021109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100000310.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 212100021109 in words is "two hundred twelve billion, one hundred million, twenty-one thousand, one hundred nine".