65720671 has 4 divisors (see below), whose sum is σ = 66139432. Its totient is φ = 65301912.

The previous prime is 65720609. The next prime is 65720693. The reversal of 65720671 is 17602756.

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

It is a cyclic number.

It is not a de Polignac number, because 65720671 - 2¹⁷ = 65589599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65720071) 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, 209145 + ... + 209458.

It is an arithmetic number, because the mean of its divisors is an integer number (16534858).

Almost surely, 2^65720671 is an apocalyptic number.

65720671 is a deficient number, since it is larger than the sum of its proper divisors (418761).

65720671 is a wasteful number, since it uses less digits than its factorization.

65720671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418760.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 65720671 is about 8106.8286647739. The cubic root of 65720671 is about 403.5530769126.

The spelling of 65720671 in words is "sixty-five million, seven hundred twenty thousand, six hundred seventy-one".