21532229 has 4 divisors (see below), whose sum is σ = 21624876. Its totient is φ = 21439584.

The previous prime is 21532223. The next prime is 21532237. The reversal of 21532229 is 92223512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6916900 + 14615329 = 2630^2 + 3823^2 .

It is a cyclic number.

It is not a de Polignac number, because 21532229 - 2⁸ = 21531973 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 21532198 and 21532207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21532223) 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, 45974 + ... + 46439.

It is an arithmetic number, because the mean of its divisors is an integer number (5406219).

Almost surely, 2^21532229 is an apocalyptic number.

It is an amenable number.

21532229 is a deficient number, since it is larger than the sum of its proper divisors (92647).

21532229 is an equidigital number, since it uses as much as digits as its factorization.

21532229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92646.

The product of its digits is 2160, while the sum is 26.

The square root of 21532229 is about 4640.2832887659. The cubic root of 21532229 is about 278.2037608695.

The spelling of 21532229 in words is "twenty-one million, five hundred thirty-two thousand, two hundred twenty-nine".