1316693981 has 2 divisors, whose sum is σ = 1316693982. Its totient is φ = 1316693980.

The previous prime is 1316693953. The next prime is 1316694037. The reversal of 1316693981 is 1893966131.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 766791481 + 549902500 = 27691^2 + 23450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1316693981 is a prime.

It is a super-2 number, since 2×1316693981² = 3467366079203256722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1316693921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 658346990 + 658346991.

It is an arithmetic number, because the mean of its divisors is an integer number (658346991).

Almost surely, 2^1316693981 is an apocalyptic number.

It is an amenable number.

1316693981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1316693981 is an equidigital number, since it uses as much as digits as its factorization.

1316693981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 47.

The square root of 1316693981 is about 36286.2781365077. The cubic root of 1316693981 is about 1096.0447431096.

The spelling of 1316693981 in words is "one billion, three hundred sixteen million, six hundred ninety-three thousand, nine hundred eighty-one".