65664131 has 4 divisors (see below), whose sum is σ = 70715232. Its totient is φ = 60613032.

The previous prime is 65664127. The next prime is 65664163. The reversal of 65664131 is 13146656.

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 65664131 - 2² = 65664127 is a prime.

It is a super-2 number, since 2×65664131² = 8623556199970322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65664101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2525531 + ... + 2525556.

It is an arithmetic number, because the mean of its divisors is an integer number (17678808).

Almost surely, 2^65664131 is an apocalyptic number.

65664131 is a deficient number, since it is larger than the sum of its proper divisors (5051101).

65664131 is a wasteful number, since it uses less digits than its factorization.

65664131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5051100.

The product of its digits is 12960, while the sum is 32.

The square root of 65664131 is about 8103.3407308344. The cubic root of 65664131 is about 403.4373171020.

The spelling of 65664131 in words is "sixty-five million, six hundred sixty-four thousand, one hundred thirty-one".