65665139 has 4 divisors (see below), whose sum is σ = 65717760. Its totient is φ = 65612520.

The previous prime is 65665133. The next prime is 65665163. The reversal of 65665139 is 93156656.

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 65665139 - 2⁴ = 65665123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 65665096 and 65665105.

It is not an unprimeable number, because it can be changed into a prime (65665133) 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, 24392 + ... + 26949.

It is an arithmetic number, because the mean of its divisors is an integer number (16429440).

Almost surely, 2^65665139 is an apocalyptic number.

65665139 is a deficient number, since it is larger than the sum of its proper divisors (52621).

65665139 is a wasteful number, since it uses less digits than its factorization.

65665139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52620.

The product of its digits is 145800, while the sum is 41.

The square root of 65665139 is about 8103.4029271658. The cubic root of 65665139 is about 403.4393814595.

The spelling of 65665139 in words is "sixty-five million, six hundred sixty-five thousand, one hundred thirty-nine".