21033021128 has 32 divisors (see below), whose sum is σ = 47442907200. Its totient is φ = 8539722432.

The previous prime is 21033021127. The next prime is 21033021131. The reversal of 21033021128 is 82112033012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21033021127) 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, 9882875 + ... + 9885002.

It is an arithmetic number, because the mean of its divisors is an integer number (1482590850).

Almost surely, 2^21033021128 is an apocalyptic number.

21033021128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21033021128 is an abundant number, since it is smaller than the sum of its proper divisors (26409886072).

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

21033021128 is a wasteful number, since it uses less digits than its factorization.

21033021128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19767909 (or 19767905 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The spelling of 21033021128 in words is "twenty-one billion, thirty-three million, twenty-one thousand, one hundred twenty-eight".