128849121 has 6 divisors (see below), whose sum is σ = 186115410. Its totient is φ = 85899408.

The previous prime is 128849099. The next prime is 128849131. The reversal of 128849121 is 121948821.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 93315600 + 35533521 = 9660^2 + 5961^2 .

It is not a de Polignac number, because 128849121 - 2⁶ = 128849057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128849131) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7158276 + ... + 7158293.

It is an arithmetic number, because the mean of its divisors is an integer number (31019235).

Almost surely, 2^128849121 is an apocalyptic number.

It is an amenable number.

128849121 is a deficient number, since it is larger than the sum of its proper divisors (57266289).

128849121 is a wasteful number, since it uses less digits than its factorization.

128849121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14316575 (or 14316572 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 128849121 is about 11351.1726706979. The cubic root of 128849121 is about 505.0803662576.

The spelling of 128849121 in words is "one hundred twenty-eight million, eight hundred forty-nine thousand, one hundred twenty-one".