21118128 has 20 divisors (see below), whose sum is σ = 54555288. Its totient is φ = 7039360.

The previous prime is 21118103. The next prime is 21118129. The reversal of 21118128 is 82181112.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21118098 and 21118107.

It is not an unprimeable number, because it can be changed into a prime (21118129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219933 + ... + 220028.

Almost surely, 2^21118128 is an apocalyptic number.

It is an amenable number.

21118128 is an abundant number, since it is smaller than the sum of its proper divisors (33437160).

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

21118128 is a wasteful number, since it uses less digits than its factorization.

21118128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439972 (or 439966 counting only the distinct ones).

The product of its digits is 256, while the sum is 24.

The square root of 21118128 is about 4595.4464418596. The cubic root of 21118128 is about 276.4087620953.

The spelling of 21118128 in words is "twenty-one million, one hundred eighteen thousand, one hundred twenty-eight".