231131212211 has 4 divisors (see below), whose sum is σ = 232549195272. Its totient is φ = 229713229152.

The previous prime is 231131212189. The next prime is 231131212219. The reversal of 231131212211 is 112212131132.

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

It is a cyclic number.

It is not a de Polignac number, because 231131212211 - 2¹⁸ = 231130950067 is a prime.

It is a super-3 number, since 3×231131212211³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231131212219) 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, 708991286 + ... + 708991611.

It is an arithmetic number, because the mean of its divisors is an integer number (58137298818).

Almost surely, 2^231131212211 is an apocalyptic number.

231131212211 is a deficient number, since it is larger than the sum of its proper divisors (1417983061).

231131212211 is a wasteful number, since it uses less digits than its factorization.

231131212211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1417983060.

The product of its digits is 144, while the sum is 20.

Adding to 231131212211 its reverse (112212131132), we get a palindrome (343343343343).

The spelling of 231131212211 in words is "two hundred thirty-one billion, one hundred thirty-one million, two hundred twelve thousand, two hundred eleven".