65664013 has 4 divisors (see below), whose sum is σ = 69526620. Its totient is φ = 61801408.

The previous prime is 65663993. The next prime is 65664037. The reversal of 65664013 is 31046656.

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

It can be written as a sum of positive squares in 2 ways, for example, as 52099524 + 13564489 = 7218^2 + 3683^2 .

It is a cyclic number.

It is not a de Polignac number, because 65664013 - 2⁹ = 65663501 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 (65664043) 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, 1931278 + ... + 1931311.

It is an arithmetic number, because the mean of its divisors is an integer number (17381655).

Almost surely, 2^65664013 is an apocalyptic number.

It is an amenable number.

65664013 is a deficient number, since it is larger than the sum of its proper divisors (3862607).

65664013 is a wasteful number, since it uses less digits than its factorization.

65664013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3862606.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 65664013 is about 8103.3334498834. Note that the first 3 decimals coincide. The cubic root of 65664013 is about 403.4370754397.

The spelling of 65664013 in words is "sixty-five million, six hundred sixty-four thousand, thirteen".