680102021 has 2 divisors, whose sum is σ = 680102022. Its totient is φ = 680102020.

The previous prime is 680102011. The next prime is 680102023. The reversal of 680102021 is 120201086.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 551733121 + 128368900 = 23489^2 + 11330^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-680102021 is a prime.

Together with 680102023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 680101984 and 680102002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (680102023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340051010 + 340051011.

It is an arithmetic number, because the mean of its divisors is an integer number (340051011).

Almost surely, 2^680102021 is an apocalyptic number.

It is an amenable number.

680102021 is a deficient number, since it is larger than the sum of its proper divisors (1).

680102021 is an equidigital number, since it uses as much as digits as its factorization.

680102021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 680102021 is about 26078.7657108230. The cubic root of 680102021 is about 879.4099095815.

The spelling of 680102021 in words is "six hundred eighty million, one hundred two thousand, twenty-one".