1312231997 has 2 divisors, whose sum is σ = 1312231998. Its totient is φ = 1312231996.

The previous prime is 1312231981. The next prime is 1312232083. The reversal of 1312231997 is 7991322131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1295208121 + 17023876 = 35989^2 + 4126^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312231997 - 2⁴ = 1312231981 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1312231997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312231927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656115998 + 656115999.

It is an arithmetic number, because the mean of its divisors is an integer number (656115999).

Almost surely, 2^1312231997 is an apocalyptic number.

It is an amenable number.

1312231997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312231997 is an equidigital number, since it uses as much as digits as its factorization.

1312231997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 38.

The square root of 1312231997 is about 36224.7428838356. The cubic root of 1312231997 is about 1094.8052577234.

The spelling of 1312231997 in words is "one billion, three hundred twelve million, two hundred thirty-one thousand, nine hundred ninety-seven".