21532241 has 4 divisors (see below), whose sum is σ = 21835584. Its totient is φ = 21228900.

The previous prime is 21532237. The next prime is 21532249. The reversal of 21532241 is 14223512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21532241 - 2² = 21532237 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21532249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151565 + ... + 151706.

It is an arithmetic number, because the mean of its divisors is an integer number (5458896).

Almost surely, 2^21532241 is an apocalyptic number.

It is an amenable number.

21532241 is a deficient number, since it is larger than the sum of its proper divisors (303343).

21532241 is an equidigital number, since it uses as much as digits as its factorization.

21532241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303342.

The product of its digits is 480, while the sum is 20.

The square root of 21532241 is about 4640.2845817902. The cubic root of 21532241 is about 278.2038125509.

Adding to 21532241 its reverse (14223512), we get a palindrome (35755753).

The spelling of 21532241 in words is "twenty-one million, five hundred thirty-two thousand, two hundred forty-one".