683855981 has 4 divisors (see below), whose sum is σ = 685480764. Its totient is φ = 682231200.

The previous prime is 683855971. The next prime is 683855983. The reversal of 683855981 is 189558386.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6295081 + 677560900 = 2509^2 + 26030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-683855981 is a prime.

It is a super-2 number, since 2×683855981² = 935318005498944722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (683855983) 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 in 3 ways as a sum of consecutive naturals, for example, 811760 + ... + 812601.

It is an arithmetic number, because the mean of its divisors is an integer number (171370191).

Almost surely, 2^683855981 is an apocalyptic number.

It is an amenable number.

683855981 is a deficient number, since it is larger than the sum of its proper divisors (1624783).

683855981 is a wasteful number, since it uses less digits than its factorization.

683855981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1624782.

The product of its digits is 2073600, while the sum is 53.

The square root of 683855981 is about 26150.6401642484. The cubic root of 683855981 is about 881.0249683387.

The spelling of 683855981 in words is "six hundred eighty-three million, eight hundred fifty-five thousand, nine hundred eighty-one".