680558021 has 16 divisors (see below), whose sum is σ = 803755008. Its totient is φ = 568084800.

The previous prime is 680557967. The next prime is 680558023. The reversal of 680558021 is 120855086.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 680558021 - 2¹⁰ = 680556997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680558023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14855 + ... + 39771.

It is an arithmetic number, because the mean of its divisors is an integer number (50234688).

Almost surely, 2^680558021 is an apocalyptic number.

It is an amenable number.

680558021 is a deficient number, since it is larger than the sum of its proper divisors (123196987).

680558021 is a wasteful number, since it uses less digits than its factorization.

680558021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25132.

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 680558021 is about 26087.5069908951. The cubic root of 680558021 is about 879.6064101630.

The spelling of 680558021 in words is "six hundred eighty million, five hundred fifty-eight thousand, twenty-one".