121280128 has 16 divisors (see below), whose sum is σ = 241613010. Its totient is φ = 60640000.

The previous prime is 121280123. The next prime is 121280143. The reversal of 121280128 is 821082121.

It can be written as a sum of positive squares in only one way, i.e., 115089984 + 6190144 = 10728^2 + 2488^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (121280123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 473623 + ... + 473878.

Almost surely, 2^121280128 is an apocalyptic number.

It is an amenable number.

121280128 is a deficient number, since it is larger than the sum of its proper divisors (120332882).

121280128 is an frugal number, since it uses more digits than its factorization.

121280128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947515 (or 947503 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 121280128 is about 11012.7257298091. The cubic root of 121280128 is about 494.9901409457.

The spelling of 121280128 in words is "one hundred twenty-one million, two hundred eighty thousand, one hundred twenty-eight".