21532225 has 48 divisors (see below), whose sum is σ = 33122880. Its totient is φ = 13651200.

The previous prime is 21532223. The next prime is 21532237. The reversal of 21532225 is 52223512.

It is not a de Polignac number, because 21532225 - 2¹ = 21532223 is a prime.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 21532196 and 21532205.

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 47 ways as a sum of consecutive naturals, for example, 67767 + ... + 68083.

It is an arithmetic number, because the mean of its divisors is an integer number (690060).

Almost surely, 2^21532225 is an apocalyptic number.

21532225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21532225 is a deficient number, since it is larger than the sum of its proper divisors (11590655).

21532225 is a wasteful number, since it uses less digits than its factorization.

21532225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370 (or 365 counting only the distinct ones).

The product of its digits is 1200, while the sum is 22.

The square root of 21532225 is about 4640.2828577577. The cubic root of 21532225 is about 278.2037436424.

Adding to 21532225 its reverse (52223512), we get a palindrome (73755737).

The spelling of 21532225 in words is "twenty-one million, five hundred thirty-two thousand, two hundred twenty-five".