681621727 has 2 divisors, whose sum is σ = 681621728. Its totient is φ = 681621726.

The previous prime is 681621709. The next prime is 681621737. The reversal of 681621727 is 727126186.

681621727 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 is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681621727 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 681621727.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681621737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340810863 + 340810864.

It is an arithmetic number, because the mean of its divisors is an integer number (340810864).

Almost surely, 2^681621727 is an apocalyptic number.

681621727 is a deficient number, since it is larger than the sum of its proper divisors (1).

681621727 is an equidigital number, since it uses as much as digits as its factorization.

681621727 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 40.

The square root of 681621727 is about 26107.8862989710. The cubic root of 681621727 is about 880.0644438859.

The spelling of 681621727 in words is "six hundred eighty-one million, six hundred twenty-one thousand, seven hundred twenty-seven".