21752 has 8 divisors (see below), whose sum is σ = 40800. Its totient is φ = 10872.

The previous prime is 21751. The next prime is 21757. The reversal of 21752 is 25712.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21752.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1352 + ... + 1367.

It is an arithmetic number, because the mean of its divisors is an integer number (5100).

2²¹⁷⁵² is an apocalyptic number.

It is an amenable number.

21752 is a deficient number, since it is larger than the sum of its proper divisors (19048).

21752 is a wasteful number, since it uses less digits than its factorization.

21752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2725 (or 2721 counting only the distinct ones).

The product of its digits is 140, while the sum is 17.

The square root of 21752 is about 147.4855925167. The cubic root of 21752 is about 27.9147064290.

Subtracting from 21752 its product of digits (140), we obtain a palindrome (21612).

The spelling of 21752 in words is "twenty-one thousand, seven hundred fifty-two".