683681021 has 2 divisors, whose sum is σ = 683681022. Its totient is φ = 683681020.

The previous prime is 683680981. The next prime is 683681029. The reversal of 683681021 is 120186386.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 608164921 + 75516100 = 24661^2 + 8690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-683681021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (683681029) 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, 341840510 + 341840511.

It is an arithmetic number, because the mean of its divisors is an integer number (341840511).

Almost surely, 2^683681021 is an apocalyptic number.

It is an amenable number.

683681021 is a deficient number, since it is larger than the sum of its proper divisors (1).

683681021 is an equidigital number, since it uses as much as digits as its factorization.

683681021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 683681021 is about 26147.2947166624. The cubic root of 683681021 is about 880.9498271393.

The spelling of 683681021 in words is "six hundred eighty-three million, six hundred eighty-one thousand, twenty-one".