21128113 has 8 divisors (see below), whose sum is σ = 21422880. Its totient is φ = 20835360.

The previous prime is 21128087. The next prime is 21128117. The reversal of 21128113 is 31182112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21128113 - 2¹³ = 21119921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21128117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40293 + ... + 40813.

It is an arithmetic number, because the mean of its divisors is an integer number (2677860).

Almost surely, 2^21128113 is an apocalyptic number.

It is an amenable number.

21128113 is a deficient number, since it is larger than the sum of its proper divisors (294767).

21128113 is a wasteful number, since it uses less digits than its factorization.

21128113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007.

The product of its digits is 96, while the sum is 19.

The square root of 21128113 is about 4596.5327149929. The cubic root of 21128113 is about 276.4523187752.

The spelling of 21128113 in words is "twenty-one million, one hundred twenty-eight thousand, one hundred thirteen".