71728281 has 32 divisors (see below), whose sum is σ = 111139200. Its totient is φ = 45662400.

The previous prime is 71728271. The next prime is 71728289. The reversal of 71728281 is 18282717.

It is a happy number.

It is not a de Polignac number, because 71728281 - 2¹⁷ = 71597209 is a prime.

It is a super-2 number, since 2×71728281² = 10289892590429922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71728289) 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 in 31 ways as a sum of consecutive naturals, for example, 78630 + ... + 79536.

It is an arithmetic number, because the mean of its divisors is an integer number (3473100).

Almost surely, 2^71728281 is an apocalyptic number.

It is an amenable number.

71728281 is a deficient number, since it is larger than the sum of its proper divisors (39410919).

71728281 is a wasteful number, since it uses less digits than its factorization.

71728281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046 (or 1040 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 71728281 is about 8469.2550439811. The cubic root of 71728281 is about 415.4927731413.

The spelling of 71728281 in words is "seventy-one million, seven hundred twenty-eight thousand, two hundred eighty-one".