21020122128 has 40 divisors (see below), whose sum is σ = 54321085728. Its totient is φ = 7004242432.

The previous prime is 21020122093. The next prime is 21020122129. The reversal of 21020122128 is 82122102012.

It is not an unprimeable number, because it can be changed into a prime (21020122129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63475 + ... + 214637.

Almost surely, 2^21020122128 is an apocalyptic number.

It is an amenable number.

21020122128 is an abundant number, since it is smaller than the sum of its proper divisors (33300963600).

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

21020122128 is a wasteful number, since it uses less digits than its factorization.

21020122128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154071 (or 154065 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The spelling of 21020122128 in words is "twenty-one billion, twenty million, one hundred twenty-two thousand, one hundred twenty-eight".