727173721 has 4 divisors (see below), whose sum is σ = 727266100. Its totient is φ = 727081344.

The previous prime is 727173709. The next prime is 727173737. The reversal of 727173721 is 127371727.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 631818496 + 95355225 = 25136^2 + 9765^2 .

It is a cyclic number.

It is not a de Polignac number, because 727173721 - 2⁷ = 727173593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (727173751) 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 in 3 ways as a sum of consecutive naturals, for example, 33156 + ... + 50533.

It is an arithmetic number, because the mean of its divisors is an integer number (181816525).

Almost surely, 2^727173721 is an apocalyptic number.

It is an amenable number.

727173721 is a deficient number, since it is larger than the sum of its proper divisors (92379).

727173721 is an equidigital number, since it uses as much as digits as its factorization.

727173721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92378.

The product of its digits is 28812, while the sum is 37.

The square root of 727173721 is about 26966.1588106278. The cubic root of 727173721 is about 899.2478163864.

The spelling of 727173721 in words is "seven hundred twenty-seven million, one hundred seventy-three thousand, seven hundred twenty-one".