681885973 has 4 divisors (see below), whose sum is σ = 683405100. Its totient is φ = 680366848.

The previous prime is 681885949. The next prime is 681885977. The reversal of 681885973 is 379588186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 379588186 = 2 ⋅189794093.

It can be written as a sum of positive squares in 2 ways, for example, as 365650884 + 316235089 = 19122^2 + 17783^2 .

It is a cyclic number.

It is not a de Polignac number, because 681885973 - 2²⁹ = 145015061 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 (681885977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 758890 + ... + 759787.

It is an arithmetic number, because the mean of its divisors is an integer number (170851275).

Almost surely, 2^681885973 is an apocalyptic number.

It is an amenable number.

681885973 is a deficient number, since it is larger than the sum of its proper divisors (1519127).

681885973 is a wasteful number, since it uses less digits than its factorization.

681885973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519126.

The product of its digits is 2903040, while the sum is 55.

The square root of 681885973 is about 26112.9464633924. The cubic root of 681885973 is about 880.1781547878.

The spelling of 681885973 in words is "six hundred eighty-one million, eight hundred eighty-five thousand, nine hundred seventy-three".