71028665 has 4 divisors (see below), whose sum is σ = 85234404. Its totient is φ = 56822928.

The previous prime is 71028611. The next prime is 71028689. The reversal of 71028665 is 56682017.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56682017 = 7 ⋅8097431.

It can be written as a sum of positive squares in 2 ways, for example, as 8048569 + 62980096 = 2837^2 + 7936^2 .

It is a cyclic number.

It is not a de Polignac number, because 71028665 - 2¹⁶ = 70963129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 7102862 + ... + 7102871.

It is an arithmetic number, because the mean of its divisors is an integer number (21308601).

Almost surely, 2^71028665 is an apocalyptic number.

It is an amenable number.

71028665 is a deficient number, since it is larger than the sum of its proper divisors (14205739).

71028665 is a wasteful number, since it uses less digits than its factorization.

71028665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14205738.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 71028665 is about 8427.8505563400. The cubic root of 71028665 is about 414.1374935200.

The spelling of 71028665 in words is "seventy-one million, twenty-eight thousand, six hundred sixty-five".