21252273 has 16 divisors (see below), whose sum is σ = 33502080. Its totient is φ = 11725056.

The previous prime is 21252269. The next prime is 21252281. The reversal of 21252273 is 37225212.

It is a happy number.

It is not a de Polignac number, because 21252273 - 2² = 21252269 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21252223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16840 + ... + 18057.

It is an arithmetic number, because the mean of its divisors is an integer number (2093880).

Almost surely, 2^21252273 is an apocalyptic number.

It is an amenable number.

21252273 is a deficient number, since it is larger than the sum of its proper divisors (12249807).

21252273 is a wasteful number, since it uses less digits than its factorization.

21252273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34936.

The product of its digits is 1680, while the sum is 24.

The square root of 21252273 is about 4610.0187635193. The cubic root of 21252273 is about 276.9927882842.

Adding to 21252273 its reverse (37225212), we get a palindrome (58477485).

The spelling of 21252273 in words is "twenty-one million, two hundred fifty-two thousand, two hundred seventy-three".