1312123231 has 4 divisors (see below), whose sum is σ = 1316315632. Its totient is φ = 1307930832.

The previous prime is 1312123213. The next prime is 1312123247. The reversal of 1312123231 is 1323212131.

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 1312123231 - 2¹³ = 1312115039 is a prime.

It is a super-2 number, since 2×1312123231² = 3443334746659758722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1312123199 and 1312123208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312123271) 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, 2095731 + ... + 2096356.

It is an arithmetic number, because the mean of its divisors is an integer number (329078908).

Almost surely, 2^1312123231 is an apocalyptic number.

1312123231 is a deficient number, since it is larger than the sum of its proper divisors (4192401).

1312123231 is an equidigital number, since it uses as much as digits as its factorization.

1312123231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4192400.

The product of its digits is 216, while the sum is 19.

The square root of 1312123231 is about 36223.2415860315. The cubic root of 1312123231 is about 1094.7750087839.

Adding to 1312123231 its reverse (1323212131), we get a palindrome (2635335362).

Subtracting 1312123231 from its reverse (1323212131), we obtain a square (11088900 = 3330²).

The spelling of 1312123231 in words is "one billion, three hundred twelve million, one hundred twenty-three thousand, two hundred thirty-one".