1671319981 has 2 divisors, whose sum is σ = 1671319982. Its totient is φ = 1671319980.

The previous prime is 1671319913. The next prime is 1671320041. The reversal of 1671319981 is 1899131761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 893412100 + 777907881 = 29890^2 + 27891^2 .

It is a cyclic number.

It is not a de Polignac number, because 1671319981 - 2¹¹ = 1671317933 is a prime.

It is a super-2 number, since 2×1671319981² = 5586620957779680722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1671311981) 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, 835659990 + 835659991.

It is an arithmetic number, because the mean of its divisors is an integer number (835659991).

Almost surely, 2^1671319981 is an apocalyptic number.

It is an amenable number.

1671319981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1671319981 is an equidigital number, since it uses as much as digits as its factorization.

1671319981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 46.

The square root of 1671319981 is about 40881.7805507539. The cubic root of 1671319981 is about 1186.7334990116.

The spelling of 1671319981 in words is "one billion, six hundred seventy-one million, three hundred nineteen thousand, nine hundred eighty-one".