21762225 has 27 divisors (see below), whose sum is σ = 39104299. Its totient is φ = 11569200.

The previous prime is 21762199. The next prime is 21762233. The reversal of 21762225 is 52226712.

The square root of 21762225 is 4665.

It is a perfect power (a square), and thus also a powerful number.

21762225 is a `hidden beast` number, since 2 + 17 + 622 + 25 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7834401 + 13927824 = 2799^2 + 3732^2 .

It is not a de Polignac number, because 21762225 - 2¹¹ = 21760177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 69820 + ... + 70130.

Almost surely, 2^21762225 is an apocalyptic number.

21762225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21762225 is the 4665-th square number.

21762225 is the 2333-rd centered octagonal number.

It is an amenable number.

21762225 is a deficient number, since it is larger than the sum of its proper divisors (17342074).

21762225 is an equidigital number, since it uses as much as digits as its factorization.

21762225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638 (or 319 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The cubic root of 21762225 is about 279.1907971518.

Adding to 21762225 its reverse (52226712), we get a palindrome (73988937).

The spelling of 21762225 in words is "twenty-one million, seven hundred sixty-two thousand, two hundred twenty-five".