2121211231 has 4 divisors (see below), whose sum is σ = 2122556200. Its totient is φ = 2119866264.

The previous prime is 2121211207. The next prime is 2121211237. The reversal of 2121211231 is 1321121212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121211231 is a prime.

It is a super-2 number, since 2×2121211231² = 8999074173041070722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121211237) 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, 670116 + ... + 673273.

It is an arithmetic number, because the mean of its divisors is an integer number (530639050).

Almost surely, 2^2121211231 is an apocalyptic number.

2121211231 is a deficient number, since it is larger than the sum of its proper divisors (1344969).

2121211231 is a wasteful number, since it uses less digits than its factorization.

2121211231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344968.

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

The square root of 2121211231 is about 46056.6089828593. The cubic root of 2121211231 is about 1284.8762629721.

Adding to 2121211231 its reverse (1321121212), we get a palindrome (3442332443).

The spelling of 2121211231 in words is "two billion, one hundred twenty-one million, two hundred eleven thousand, two hundred thirty-one".