65121553643 has 4 divisors (see below), whose sum is σ = 65558611200. Its totient is φ = 64684496088.

The previous prime is 65121553639. The next prime is 65121553681. The reversal of 65121553643 is 34635512156.

65121553643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 65121553643 - 2² = 65121553639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65121553643.

It is not an unprimeable number, because it can be changed into a prime (65121553603) 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, 218528555 + ... + 218528852.

It is an arithmetic number, because the mean of its divisors is an integer number (16389652800).

Almost surely, 2^65121553643 is an apocalyptic number.

65121553643 is a deficient number, since it is larger than the sum of its proper divisors (437057557).

65121553643 is a wasteful number, since it uses less digits than its factorization.

65121553643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437057556.

The product of its digits is 324000, while the sum is 41.

The spelling of 65121553643 in words is "sixty-five billion, one hundred twenty-one million, five hundred fifty-three thousand, six hundred forty-three".