128854440879649 has 3 divisors (see below), whose sum is σ = 128854452231057. Its totient is φ = 128854429528242.

The previous prime is 128854440879551. The next prime is 128854440879677. The reversal of 128854440879649 is 946978044458821.

The square root of 128854440879649 is 11351407.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a de Polignac number, because none of the positive numbers 2^k-128854440879649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128854440876649) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 5675704 + ... + 17027110.

It is an arithmetic number, because the mean of its divisors is an integer number (42951484077019).

Almost surely, 2^{128854440879649} is an apocalyptic number.

128854440879649 is the 11351407-th square number.

128854440879649 is the 5675704-th centered octagonal number.

It is an amenable number.

128854440879649 is a deficient number, since it is larger than the sum of its proper divisors (11351408).

128854440879649 is an frugal number, since it uses more digits than its factorization.

128854440879649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22702814 (or 11351407 counting only the distinct ones).

The product of its (nonzero) digits is 4459069440, while the sum is 79.

The spelling of 128854440879649 in words is "one hundred twenty-eight trillion, eight hundred fifty-four billion, four hundred forty million, eight hundred seventy-nine thousand, six hundred forty-nine".