71727221 has 2 divisors, whose sum is σ = 71727222. Its totient is φ = 71727220.

The previous prime is 71727209. The next prime is 71727241. The reversal of 71727221 is 12272717.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58140625 + 13586596 = 7625^2 + 3686^2 .

It is an emirp because it is prime and its reverse (12272717) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71727221 - 2⁶ = 71727157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71727241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35863610 + 35863611.

It is an arithmetic number, because the mean of its divisors is an integer number (35863611).

Almost surely, 2^71727221 is an apocalyptic number.

It is an amenable number.

71727221 is a deficient number, since it is larger than the sum of its proper divisors (1).

71727221 is an equidigital number, since it uses as much as digits as its factorization.

71727221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2744, while the sum is 29.

The square root of 71727221 is about 8469.1924644561. The cubic root of 71727221 is about 415.4907264148.

Adding to 71727221 its reverse (12272717), we get a palindrome (83999938).

The spelling of 71727221 in words is "seventy-one million, seven hundred twenty-seven thousand, two hundred twenty-one".