65128921247 has 4 divisors (see below), whose sum is σ = 70138838280. Its totient is φ = 60119004216.

The previous prime is 65128921237. The next prime is 65128921271. The reversal of 65128921247 is 74212982156.

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 65128921247 - 2¹⁰ = 65128920223 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 (65128921237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2504958497 + ... + 2504958522.

It is an arithmetic number, because the mean of its divisors is an integer number (17534709570).

Almost surely, 2^65128921247 is an apocalyptic number.

65128921247 is a deficient number, since it is larger than the sum of its proper divisors (5009917033).

65128921247 is a wasteful number, since it uses less digits than its factorization.

65128921247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5009917032.

The product of its digits is 483840, while the sum is 47.

The spelling of 65128921247 in words is "sixty-five billion, one hundred twenty-eight million, nine hundred twenty-one thousand, two hundred forty-seven".