21225505 has 8 divisors (see below), whose sum is σ = 29109312. Its totient is φ = 14554608.

The previous prime is 21225487. The next prime is 21225511. The reversal of 21225505 is 50552212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21225505 - 2⁵ = 21225473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303187 + ... + 303256.

It is an arithmetic number, because the mean of its divisors is an integer number (3638664).

Almost surely, 2^21225505 is an apocalyptic number.

It is an amenable number.

21225505 is a deficient number, since it is larger than the sum of its proper divisors (7883807).

21225505 is an equidigital number, since it uses as much as digits as its factorization.

21225505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606455.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 21225505 is about 4607.1146067794. The cubic root of 21225505 is about 276.8764453077.

Adding to 21225505 its reverse (50552212), we get a palindrome (71777717).

The spelling of 21225505 in words is "twenty-one million, two hundred twenty-five thousand, five hundred five".