6729097721 has 2 divisors, whose sum is σ = 6729097722. Its totient is φ = 6729097720.

The previous prime is 6729097717. The next prime is 6729097757. The reversal of 6729097721 is 1277909276.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6583050496 + 146047225 = 81136^2 + 12085^2 .

It is a cyclic number.

It is not a de Polignac number, because 6729097721 - 2² = 6729097717 is a prime.

It is a super-2 number, since 2×6729097721² = 90561512277534787682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6729097721.

It is not a weakly prime, because it can be changed into another prime (6729097121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3364548860 + 3364548861.

It is an arithmetic number, because the mean of its divisors is an integer number (3364548861).

Almost surely, 2^6729097721 is an apocalyptic number.

It is an amenable number.

6729097721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6729097721 is an equidigital number, since it uses as much as digits as its factorization.

6729097721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 666792, while the sum is 50.

The square root of 6729097721 is about 82031.0777754383. The cubic root of 6729097721 is about 1887.9288006439.

The spelling of 6729097721 in words is "six billion, seven hundred twenty-nine million, ninety-seven thousand, seven hundred twenty-one".