21166128 has 30 divisors (see below), whose sum is σ = 59236164. Its totient is φ = 7055328.

The previous prime is 21166111. The next prime is 21166129. The reversal of 21166128 is 82166112.

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

It is not an unprimeable number, because it can be changed into a prime (21166129) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73350 + ... + 73637.

Almost surely, 2^21166128 is an apocalyptic number.

It is an amenable number.

21166128 is an abundant number, since it is smaller than the sum of its proper divisors (38070036).

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

21166128 is a wasteful number, since it uses less digits than its factorization.

21166128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147001 (or 146992 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 21166128 is about 4600.6660387383. Note that the first 3 decimals coincide. The cubic root of 21166128 is about 276.6180227699.

The spelling of 21166128 in words is "twenty-one million, one hundred sixty-six thousand, one hundred twenty-eight".