211216205 has 4 divisors (see below), whose sum is σ = 253459452. Its totient is φ = 168972960.

The previous prime is 211216169. The next prime is 211216231. The reversal of 211216205 is 502612112.

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 50154724 + 161061481 = 7082^2 + 12691^2 .

It is not a de Polignac number, because 211216205 - 2²² = 207021901 is a prime.

It is a super-2 number, since 2×211216205² = 89224570509204050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21121616 + ... + 21121625.

It is an arithmetic number, because the mean of its divisors is an integer number (63364863).

Almost surely, 2^211216205 is an apocalyptic number.

It is an amenable number.

211216205 is a deficient number, since it is larger than the sum of its proper divisors (42243247).

211216205 is an equidigital number, since it uses as much as digits as its factorization.

211216205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42243246.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 211216205 is about 14533.2792239054. The cubic root of 211216205 is about 595.5374519119.

Adding to 211216205 its reverse (502612112), we get a palindrome (713828317).

The spelling of 211216205 in words is "two hundred eleven million, two hundred sixteen thousand, two hundred five".