680704991 has 2 divisors, whose sum is σ = 680704992. Its totient is φ = 680704990.

The previous prime is 680704979. The next prime is 680704993. The reversal of 680704991 is 199407086.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 680704991 - 2²² = 676510687 is a prime.

It is a super-3 number, since 3×680704991³ (a number of 27 digits) contains 333 as substring.

Together with 680704993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (680704993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340352495 + 340352496.

It is an arithmetic number, because the mean of its divisors is an integer number (340352496).

Almost surely, 2^680704991 is an apocalyptic number.

680704991 is a deficient number, since it is larger than the sum of its proper divisors (1).

680704991 is an equidigital number, since it uses as much as digits as its factorization.

680704991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 680704991 is about 26090.3237043928. The cubic root of 680704991 is about 879.6697241129.

The spelling of 680704991 in words is "six hundred eighty million, seven hundred four thousand, nine hundred ninety-one".