1681881861 has 16 divisors (see below), whose sum is σ = 2473865280. Its totient is φ = 1007867520.

The previous prime is 1681881829. The next prime is 1681881863.

1681881861 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1681881861 - 2⁵ = 1681881829 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1681881861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681881863) 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 15 ways as a sum of consecutive naturals, for example, 283390 + ... + 289263.

It is an arithmetic number, because the mean of its divisors is an integer number (154616580).

Almost surely, 2^1681881861 is an apocalyptic number.

1681881861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1681881861 is a deficient number, since it is larger than the sum of its proper divisors (791983419).

1681881861 is a wasteful number, since it uses less digits than its factorization.

1681881861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572756.

The product of its digits is 147456, while the sum is 48.

The square root of 1681881861 is about 41010.7529923556. The cubic root of 1681881861 is about 1189.2280993208.

The spelling of 1681881861 in words is "one billion, six hundred eighty-one million, eight hundred eighty-one thousand, eight hundred sixty-one".