64165844755221 has 64 divisors (see below), whose sum is σ = 99120564449280. Its totient is φ = 36513099786240.

The previous prime is 64165844755211. The next prime is 64165844755291. The reversal of 64165844755221 is 12255744856146.

It is not a de Polignac number, because 64165844755221 - 2⁶ = 64165844755157 is a prime.

It is a super-2 number, since 2×64165844755221² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64165844755211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1664766676 + ... + 1664805218.

It is an arithmetic number, because the mean of its divisors is an integer number (1548758819520).

Almost surely, 2^{64165844755221} is an apocalyptic number.

It is an amenable number.

64165844755221 is a deficient number, since it is larger than the sum of its proper divisors (34954719694059).

64165844755221 is a wasteful number, since it uses less digits than its factorization.

64165844755221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62186.

The product of its digits is 64512000, while the sum is 60.

The spelling of 64165844755221 in words is "sixty-four trillion, one hundred sixty-five billion, eight hundred forty-four million, seven hundred fifty-five thousand, two hundred twenty-one".