2121578128 has 80 divisors (see below), whose sum is σ = 4330972800. Its totient is φ = 1005788160.

The previous prime is 2121578117. The next prime is 2121578141. The reversal of 2121578128 is 8218751212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4832533 + ... + 4832971.

It is an arithmetic number, because the mean of its divisors is an integer number (54137160).

Almost surely, 2^2121578128 is an apocalyptic number.

It is an amenable number.

2121578128 is an abundant number, since it is smaller than the sum of its proper divisors (2209394672).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2121578128 is a wasteful number, since it uses less digits than its factorization.

2121578128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680 (or 674 counting only the distinct ones).

The product of its digits is 17920, while the sum is 37.

The square root of 2121578128 is about 46060.5919197745. The cubic root of 2121578128 is about 1284.9503385855.

The spelling of 2121578128 in words is "two billion, one hundred twenty-one million, five hundred seventy-eight thousand, one hundred twenty-eight".