1312231985 has 4 divisors (see below), whose sum is σ = 1574678388. Its totient is φ = 1049785584.

The previous prime is 1312231981. The next prime is 1312231997. The reversal of 1312231985 is 5891322131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5891322131 = 29 ⋅203149039.

It can be written as a sum of positive squares in 2 ways, for example, as 689430049 + 622801936 = 26257^2 + 24956^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312231985 - 2² = 1312231981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1312231981) 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, 131223194 + ... + 131223203.

It is an arithmetic number, because the mean of its divisors is an integer number (393669597).

Almost surely, 2^1312231985 is an apocalyptic number.

It is an amenable number.

1312231985 is a deficient number, since it is larger than the sum of its proper divisors (262446403).

1312231985 is an equidigital number, since it uses as much as digits as its factorization.

1312231985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262446402.

The product of its digits is 12960, while the sum is 35.

The square root of 1312231985 is about 36224.7427182030. The cubic root of 1312231985 is about 1094.8052543861.

The spelling of 1312231985 in words is "one billion, three hundred twelve million, two hundred thirty-one thousand, nine hundred eighty-five".