680487587028721 has 2 divisors, whose sum is σ = 680487587028722. Its totient is φ = 680487587028720.

The previous prime is 680487587028631. The next prime is 680487587028803. The reversal of 680487587028721 is 127820785784086.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674307888218721 + 6179698810000 = 25967439^2 + 2485900^2 .

It is a cyclic number.

It is not a de Polignac number, because 680487587028721 - 2¹³ = 680487587020529 is a prime.

It is a super-2 number, since 2×680487587028721² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (680487587026721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340243793514360 + 340243793514361.

It is an arithmetic number, because the mean of its divisors is an integer number (340243793514361).

Almost surely, 2^{680487587028721} is an apocalyptic number.

It is an amenable number.

680487587028721 is a deficient number, since it is larger than the sum of its proper divisors (1).

680487587028721 is an equidigital number, since it uses as much as digits as its factorization.

680487587028721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 674365440, while the sum is 73.

The spelling of 680487587028721 in words is "six hundred eighty trillion, four hundred eighty-seven billion, five hundred eighty-seven million, twenty-eight thousand, seven hundred twenty-one".