1681126613 has 4 divisors (see below), whose sum is σ = 1683155340. Its totient is φ = 1679097888.

The previous prime is 1681126591. The next prime is 1681126619. The reversal of 1681126613 is 3166211861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3166211861 = 8059 ⋅392879.

It can be written as a sum of positive squares in 2 ways, for example, as 1469802244 + 211324369 = 38338^2 + 14537^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681126613 - 2⁸ = 1681126357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681126619) 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 in 3 ways as a sum of consecutive naturals, for example, 1013120 + ... + 1014777.

It is an arithmetic number, because the mean of its divisors is an integer number (420788835).

Almost surely, 2^1681126613 is an apocalyptic number.

It is an amenable number.

1681126613 is a deficient number, since it is larger than the sum of its proper divisors (2028727).

1681126613 is an equidigital number, since it uses as much as digits as its factorization.

1681126613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028726.

The product of its digits is 10368, while the sum is 35.

The square root of 1681126613 is about 41001.5440319020. The cubic root of 1681126613 is about 1189.0500652908.

The spelling of 1681126613 in words is "one billion, six hundred eighty-one million, one hundred twenty-six thousand, six hundred thirteen".