21652 has 6 divisors (see below), whose sum is σ = 37898. Its totient is φ = 10824.

The previous prime is 21649. The next prime is 21661. The reversal of 21652 is 25612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15876 + 5776 = 126^2 + 76^2 .

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2703 + ... + 2710.

2²¹⁶⁵² is an apocalyptic number.

It is an amenable number.

21652 is a deficient number, since it is larger than the sum of its proper divisors (16246).

21652 is a wasteful number, since it uses less digits than its factorization.

21652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5417 (or 5415 counting only the distinct ones).

The product of its digits is 120, while the sum is 16.

The square root of 21652 is about 147.1461858153. The cubic root of 21652 is about 27.8718634824.

The spelling of 21652 in words is "twenty-one thousand, six hundred fifty-two".