128048749921 has 3 divisors (see below), whose sum is σ = 128049107761. Its totient is φ = 128048392082.

The previous prime is 128048749883. The next prime is 128048749931. The reversal of 128048749921 is 129947840821.

The square root of 128048749921 is 357839.

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, and also an emirpimes, since its reverse is a distinct semiprime: 129947840821 = 27919 ⋅4654459.

It is not a de Polignac number, because 128048749921 - 2⁷ = 128048749793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128048749931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 178920 + ... + 536758.

Almost surely, 2^128048749921 is an apocalyptic number.

128048749921 is the 357839-th square number.

128048749921 is the 178920-th centered octagonal number.

It is an amenable number.

128048749921 is a deficient number, since it is larger than the sum of its proper divisors (357840).

128048749921 is an frugal number, since it uses more digits than its factorization.

128048749921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715678 (or 357839 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 55.

It can be divided in two parts, 128048 and 749921, that added together give a square (877969 = 937²).

The spelling of 128048749921 in words is "one hundred twenty-eight billion, forty-eight million, seven hundred forty-nine thousand, nine hundred twenty-one".