683757221681 has 2 divisors, whose sum is σ = 683757221682. Its totient is φ = 683757221680.

The previous prime is 683757221657. The next prime is 683757221723. The reversal of 683757221681 is 186122757386.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 675527829025 + 8229392656 = 821905^2 + 90716^2 .

It is a cyclic number.

It is not a de Polignac number, because 683757221681 - 2⁶ = 683757221617 is a prime.

It is a super-2 number, since 2×683757221681² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (683757221611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 341878610840 + 341878610841.

It is an arithmetic number, because the mean of its divisors is an integer number (341878610841).

Almost surely, 2^683757221681 is an apocalyptic number.

It is an amenable number.

683757221681 is a deficient number, since it is larger than the sum of its proper divisors (1).

683757221681 is an equidigital number, since it uses as much as digits as its factorization.

683757221681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6773760, while the sum is 56.

The spelling of 683757221681 in words is "six hundred eighty-three billion, seven hundred fifty-seven million, two hundred twenty-one thousand, six hundred eighty-one".