128445566669 has 4 divisors (see below), whose sum is σ = 146794933344. Its totient is φ = 110096199996.

The previous prime is 128445566651. The next prime is 128445566681. The reversal of 128445566669 is 966665544821.

It is a happy number.

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 128445566669 - 2³⁶ = 59726089933 is a prime.

It is a super-2 number, since 2×128445566669² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128445562669) 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, 9174683327 + ... + 9174683340.

It is an arithmetic number, because the mean of its divisors is an integer number (36698733336).

Almost surely, 2^128445566669 is an apocalyptic number.

It is an amenable number.

128445566669 is a deficient number, since it is larger than the sum of its proper divisors (18349366675).

128445566669 is an equidigital number, since it uses as much as digits as its factorization.

128445566669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18349366674.

The product of its digits is 74649600, while the sum is 62.

The spelling of 128445566669 in words is "one hundred twenty-eight billion, four hundred forty-five million, five hundred sixty-six thousand, six hundred sixty-nine".