211225505 has 4 divisors (see below), whose sum is σ = 253470612. Its totient is φ = 168980400.

The previous prime is 211225477. The next prime is 211225507. The reversal of 211225505 is 505522112.

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 166616464 + 44609041 = 12908^2 + 6679^2 .

It is not a de Polignac number, because 211225505 - 2²⁰ = 210176929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (211225507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21122546 + ... + 21122555.

It is an arithmetic number, because the mean of its divisors is an integer number (63367653).

Almost surely, 2^211225505 is an apocalyptic number.

It is an amenable number.

211225505 is a deficient number, since it is larger than the sum of its proper divisors (42245107).

211225505 is an equidigital number, since it uses as much as digits as its factorization.

211225505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42245106.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 211225505 is about 14533.5991757032. The cubic root of 211225505 is about 595.5461924298.

Adding to 211225505 its reverse (505522112), we get a palindrome (716747617).

The spelling of 211225505 in words is "two hundred eleven million, two hundred twenty-five thousand, five hundred five".