21128652 has 36 divisors (see below), whose sum is σ = 54654600. Its totient is φ = 6878592.

The previous prime is 21128641. The next prime is 21128659. The reversal of 21128652 is 25682112.

It is a happy number.

21128652 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 8 + 652 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21128659) 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 11 ways as a sum of consecutive naturals, for example, 5277 + ... + 8372.

Almost surely, 2^21128652 is an apocalyptic number.

It is an amenable number.

21128652 is an abundant number, since it is smaller than the sum of its proper divisors (33525948).

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

21128652 is a wasteful number, since it uses less digits than its factorization.

21128652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13702 (or 13697 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 21128652 is about 4596.5913457692. The cubic root of 21128652 is about 276.4546696167.

The spelling of 21128652 in words is "twenty-one million, one hundred twenty-eight thousand, six hundred fifty-two".