128158988049 has 21 divisors (see below), whose sum is σ = 192165074713. Its totient is φ = 85432881492.

The previous prime is 128158987997. The next prime is 128158988053. The reversal of 128158988049 is 940889851821.

The square root of 128158988049 is 357993.

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

128158988049 is a `hidden beast` number, since 1 + 2 + 8 + 1 + 589 + 8 + 8 + 0 + 49 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-128158988049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128158988449) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 9659182 + ... + 9672440.

Almost surely, 2^128158988049 is an apocalyptic number.

128158988049 is the 357993-rd square number.

128158988049 is the 178997-th centered octagonal number.

It is an amenable number.

128158988049 is a deficient number, since it is larger than the sum of its proper divisors (64006086664).

128158988049 is an frugal number, since it uses more digits than its factorization.

128158988049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26536 (or 13262 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 63.

The spelling of 128158988049 in words is "one hundred twenty-eight billion, one hundred fifty-eight million, nine hundred eighty-eight thousand, forty-nine".