211205125 has 8 divisors (see below), whose sum is σ = 263584152. Its totient is φ = 168964000.

The previous prime is 211205117. The next prime is 211205129. The reversal of 211205125 is 521502112.

It can be written as a sum of positive squares in 4 ways, for example, as 171396 + 211033729 = 414^2 + 14527^2 .

It is not a de Polignac number, because 211205125 - 2³ = 211205117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211205129) 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 7 ways as a sum of consecutive naturals, for example, 844696 + ... + 844945.

It is an arithmetic number, because the mean of its divisors is an integer number (32948019).

Almost surely, 2^211205125 is an apocalyptic number.

211205125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

211205125 is a deficient number, since it is larger than the sum of its proper divisors (52379027).

211205125 is an equidigital number, since it uses as much as digits as its factorization.

211205125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1689656 (or 1689646 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 211205125 is about 14532.8980248263. The cubic root of 211205125 is about 595.5270381429.

Adding to 211205125 its reverse (521502112), we get a palindrome (732707237).

The spelling of 211205125 in words is "two hundred eleven million, two hundred five thousand, one hundred twenty-five".