211231002121 has 4 divisors (see below), whose sum is σ = 211232637252. Its totient is φ = 211229366992.

The previous prime is 211231002119. The next prime is 211231002209. The reversal of 211231002121 is 121200132112.

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 121748655625 + 89482346496 = 348925^2 + 299136^2 .

It is a cyclic number.

It is not a de Polignac number, because 211231002121 - 2¹ = 211231002119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211231002095 and 211231002104.

It is not an unprimeable number, because it can be changed into a prime (211231002721) 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 3 ways as a sum of consecutive naturals, for example, 605446 + ... + 888271.

It is an arithmetic number, because the mean of its divisors is an integer number (52808159313).

Almost surely, 2^211231002121 is an apocalyptic number.

It is an amenable number.

211231002121 is a deficient number, since it is larger than the sum of its proper divisors (1635131).

211231002121 is a wasteful number, since it uses less digits than its factorization.

211231002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1635130.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 211231002121 its reverse (121200132112), we get a palindrome (332431134233).

The spelling of 211231002121 in words is "two hundred eleven billion, two hundred thirty-one million, two thousand, one hundred twenty-one".