71128769 has 4 divisors (see below), whose sum is σ = 71486400. Its totient is φ = 70771140.

The previous prime is 71128753. The next prime is 71128789. The reversal of 71128769 is 96782117.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96782117 = 347 ⋅278911.

It is a cyclic number.

It is not a de Polignac number, because 71128769 - 2⁴ = 71128753 is a prime.

It is a super-2 number, since 2×71128769² = 10118603558910722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (71128789) 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 3 ways as a sum of consecutive naturals, for example, 178517 + ... + 178914.

It is an arithmetic number, because the mean of its divisors is an integer number (17871600).

Almost surely, 2^71128769 is an apocalyptic number.

It is an amenable number.

71128769 is a deficient number, since it is larger than the sum of its proper divisors (357631).

71128769 is a wasteful number, since it uses less digits than its factorization.

71128769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357630.

The product of its digits is 42336, while the sum is 41.

The square root of 71128769 is about 8433.7873461453. The cubic root of 71128769 is about 414.3319566015.

The spelling of 71128769 in words is "seventy-one million, one hundred twenty-eight thousand, seven hundred sixty-nine".