1381207981 has 2 divisors, whose sum is σ = 1381207982. Its totient is φ = 1381207980.

The previous prime is 1381207967. The next prime is 1381208051. The reversal of 1381207981 is 1897021831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1047816900 + 333391081 = 32370^2 + 18259^2 .

It is an emirp because it is prime and its reverse (1897021831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1381207981 - 2¹¹ = 1381205933 is a prime.

It is a super-2 number, since 2×1381207981² = 3815470973556192722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1381207901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690603990 + 690603991.

It is an arithmetic number, because the mean of its divisors is an integer number (690603991).

Almost surely, 2^1381207981 is an apocalyptic number.

It is an amenable number.

1381207981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381207981 is an equidigital number, since it uses as much as digits as its factorization.

1381207981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 1381207981 is about 37164.6065632343. The cubic root of 1381207981 is about 1113.6610392142.

The spelling of 1381207981 in words is "one billion, three hundred eighty-one million, two hundred seven thousand, nine hundred eighty-one".