1681951673 has 2 divisors, whose sum is σ = 1681951674. Its totient is φ = 1681951672.

The previous prime is 1681951639. The next prime is 1681951709. The reversal of 1681951673 is 3761591861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1401154624 + 280797049 = 37432^2 + 16757^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681951673 - 2¹⁰ = 1681950649 is a prime.

It is a super-2 number, since 2×1681951673² = 5657922860614997858, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1681951273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840975836 + 840975837.

It is an arithmetic number, because the mean of its divisors is an integer number (840975837).

Almost surely, 2^1681951673 is an apocalyptic number.

It is an amenable number.

1681951673 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681951673 is an equidigital number, since it uses as much as digits as its factorization.

1681951673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 272160, while the sum is 47.

The square root of 1681951673 is about 41011.6041261495. The cubic root of 1681951673 is about 1189.2445533586.

The spelling of 1681951673 in words is "one billion, six hundred eighty-one million, nine hundred fifty-one thousand, six hundred seventy-three".