65644879137 has 4 divisors (see below), whose sum is σ = 87526505520. Its totient is φ = 43763252756.

The previous prime is 65644879121. The next prime is 65644879147. The reversal of 65644879137 is 73197844656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65644879137 - 2⁴ = 65644879121 is a prime.

It is a super-2 number, since 2×65644879137² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (65644879147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10940813187 + ... + 10940813192.

It is an arithmetic number, because the mean of its divisors is an integer number (21881626380).

Almost surely, 2^65644879137 is an apocalyptic number.

It is an amenable number.

65644879137 is a deficient number, since it is larger than the sum of its proper divisors (21881626383).

65644879137 is a wasteful number, since it uses less digits than its factorization.

65644879137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21881626382.

The product of its digits is 30481920, while the sum is 60.

The spelling of 65644879137 in words is "sixty-five billion, six hundred forty-four million, eight hundred seventy-nine thousand, one hundred thirty-seven".