65720665 has 8 divisors (see below), whose sum is σ = 78965568. Its totient is φ = 52509360.

The previous prime is 65720609. The next prime is 65720693. The reversal of 65720665 is 56602756.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 65720665 - 2⁹ = 65720153 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3871 + ... + 12100.

It is an arithmetic number, because the mean of its divisors is an integer number (9870696).

Almost surely, 2^65720665 is an apocalyptic number.

It is an amenable number.

65720665 is a deficient number, since it is larger than the sum of its proper divisors (13244903).

65720665 is a wasteful number, since it uses less digits than its factorization.

65720665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16799.

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 65720665 is about 8106.8282947155. The cubic root of 65720665 is about 403.5530646317.

The spelling of 65720665 in words is "sixty-five million, seven hundred twenty thousand, six hundred sixty-five".