727768721 has 2 divisors, whose sum is σ = 727768722. Its totient is φ = 727768720.

The previous prime is 727768669. The next prime is 727768729. The reversal of 727768721 is 127867727.

727768721 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., 408646225 + 319122496 = 20215^2 + 17864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-727768721 is a prime.

It is a super-2 number, since 2×727768721² = 1059294622531951682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (727768729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 363884360 + 363884361.

It is an arithmetic number, because the mean of its divisors is an integer number (363884361).

Almost surely, 2^727768721 is an apocalyptic number.

It is an amenable number.

727768721 is a deficient number, since it is larger than the sum of its proper divisors (1).

727768721 is an equidigital number, since it uses as much as digits as its factorization.

727768721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 460992, while the sum is 47.

The square root of 727768721 is about 26977.1889009956. The cubic root of 727768721 is about 899.4930152839.

The spelling of 727768721 in words is "seven hundred twenty-seven million, seven hundred sixty-eight thousand, seven hundred twenty-one".