128191209444 has 45 divisors (see below), whose sum is σ = 335133991731. Its totient is φ = 42728254920.

The previous prime is 128191209437. The next prime is 128191209451. The reversal of 128191209444 is 444902191821.

The square root of 128191209444 is 358038.

It is a perfect power (a square), and thus also a powerful number.

128191209444 is a `hidden beast` number, since 1 + 2 + 81 + 9 + 120 + 9 + 444 = 666.

It is an interprime number because it is at equal distance from previous prime (128191209437) and next prime (128191209451).

It is a self number, because there is not a number n which added to its sum of digits gives 128191209444.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 6434739 + ... + 6454629.

Almost surely, 2^128191209444 is an apocalyptic number.

128191209444 is the 358038-th square number.

It is an amenable number.

128191209444 is an abundant number, since it is smaller than the sum of its proper divisors (206942782287).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128191209444 is an frugal number, since it uses more digits than its factorization.

128191209444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39798 (or 19896 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 128191209444 in words is "one hundred twenty-eight billion, one hundred ninety-one million, two hundred nine thousand, four hundred forty-four".