680865421 has 2 divisors, whose sum is σ = 680865422. Its totient is φ = 680865420.

The previous prime is 680865413. The next prime is 680865439. The reversal of 680865421 is 124568086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 675272196 + 5593225 = 25986^2 + 2365^2 .

It is a cyclic number.

It is not a de Polignac number, because 680865421 - 2³ = 680865413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (680865491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340432710 + 340432711.

It is an arithmetic number, because the mean of its divisors is an integer number (340432711).

Almost surely, 2^680865421 is an apocalyptic number.

It is an amenable number.

680865421 is a deficient number, since it is larger than the sum of its proper divisors (1).

680865421 is an equidigital number, since it uses as much as digits as its factorization.

680865421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 680865421 is about 26093.3980347520. The cubic root of 680865421 is about 879.7388261616.

The spelling of 680865421 in words is "six hundred eighty million, eight hundred sixty-five thousand, four hundred twenty-one".