1312409981 has 2 divisors, whose sum is σ = 1312409982. Its totient is φ = 1312409980.

The previous prime is 1312409977. The next prime is 1312410023. The reversal of 1312409981 is 1899042131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1206937081 + 105472900 = 34741^2 + 10270^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312409981 - 2² = 1312409977 is a prime.

It is a super-2 number, since 2×1312409981² = 3444839916456840722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312409951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656204990 + 656204991.

It is an arithmetic number, because the mean of its divisors is an integer number (656204991).

Almost surely, 2^1312409981 is an apocalyptic number.

It is an amenable number.

1312409981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312409981 is an equidigital number, since it uses as much as digits as its factorization.

1312409981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 1312409981 is about 36227.1994639387. The cubic root of 1312409981 is about 1094.8547532928.

The spelling of 1312409981 in words is "one billion, three hundred twelve million, four hundred nine thousand, nine hundred eighty-one".