681435977 has 2 divisors, whose sum is σ = 681435978. Its totient is φ = 681435976.

The previous prime is 681435943. The next prime is 681436003. The reversal of 681435977 is 779534186.

681435977 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 681418816 + 17161 = 26104^2 + 131^2 .

It is a cyclic number.

It is not a de Polignac number, because 681435977 - 2⁸ = 681435721 is a prime.

It is not a weakly prime, because it can be changed into another prime (681435917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340717988 + 340717989.

It is an arithmetic number, because the mean of its divisors is an integer number (340717989).

Almost surely, 2^681435977 is an apocalyptic number.

It is an amenable number.

681435977 is a deficient number, since it is larger than the sum of its proper divisors (1).

681435977 is an equidigital number, since it uses as much as digits as its factorization.

681435977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1270080, while the sum is 50.

The square root of 681435977 is about 26104.3287023436. The cubic root of 681435977 is about 879.9844939589.

The spelling of 681435977 in words is "six hundred eighty-one million, four hundred thirty-five thousand, nine hundred seventy-seven".