212001121 has 4 divisors (see below), whose sum is σ = 214100244. Its totient is φ = 209902000.

The previous prime is 212001109. The next prime is 212001149. The reversal of 212001121 is 121100212.

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 160376896 + 51624225 = 12664^2 + 7185^2 .

It is a cyclic number.

It is not a de Polignac number, because 212001121 - 2⁹ = 212000609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212001098 and 212001107.

It is not an unprimeable number, because it can be changed into a prime (212001821) 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, 1049410 + ... + 1049611.

It is an arithmetic number, because the mean of its divisors is an integer number (53525061).

Almost surely, 2^212001121 is an apocalyptic number.

It is an amenable number.

212001121 is a deficient number, since it is larger than the sum of its proper divisors (2099123).

212001121 is a wasteful number, since it uses less digits than its factorization.

212001121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2099122.

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

The square root of 212001121 is about 14560.2582738082. The cubic root of 212001121 is about 596.2742467509.

Adding to 212001121 its reverse (121100212), we get a palindrome (333101333).

Subtracting from 212001121 its reverse (121100212), we obtain a palindrome (90900909).

The spelling of 212001121 in words is "two hundred twelve million, one thousand, one hundred twenty-one".