21355652 has 12 divisors (see below), whose sum is σ = 38578176. Its totient is φ = 10333320.

The previous prime is 21355637. The next prime is 21355657. The reversal of 21355652 is 25655312.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21355657) 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 3 ways as a sum of consecutive naturals, for example, 85988 + ... + 86235.

It is an arithmetic number, because the mean of its divisors is an integer number (3214848).

Almost surely, 2^21355652 is an apocalyptic number.

It is an amenable number.

21355652 is a deficient number, since it is larger than the sum of its proper divisors (17222524).

21355652 is a wasteful number, since it uses less digits than its factorization.

21355652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172258 (or 172256 counting only the distinct ones).

The product of its digits is 9000, while the sum is 29.

The square root of 21355652 is about 4621.2175884717. The cubic root of 21355652 is about 277.4411941512.

The spelling of 21355652 in words is "twenty-one million, three hundred fifty-five thousand, six hundred fifty-two".