21662128 has 20 divisors (see below), whose sum is σ = 44179960. Its totient is φ = 10260864.

The previous prime is 21662117. The next prime is 21662129. The reversal of 21662128 is 82126612.

It is a junction number, because it is equal to n+sod(n) for n = 21662096 and 21662105.

It is not an unprimeable number, because it can be changed into a prime (21662129) 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, 35325 + ... + 35932.

It is an arithmetic number, because the mean of its divisors is an integer number (2208998).

Almost surely, 2^21662128 is an apocalyptic number.

It is an amenable number.

21662128 is an abundant number, since it is smaller than the sum of its proper divisors (22517832).

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

21662128 is a wasteful number, since it uses less digits than its factorization.

21662128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71284 (or 71278 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 21662128 is about 4654.2591247158. The cubic root of 21662128 is about 278.7620861189.

The spelling of 21662128 in words is "twenty-one million, six hundred sixty-two thousand, one hundred twenty-eight".