211221215 has 8 divisors (see below), whose sum is σ = 253955088. Its totient is φ = 168650560.

The previous prime is 211221169. The next prime is 211221229. The reversal of 211221215 is 512122112.

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

It is not a de Polignac number, because 211221215 - 2²⁶ = 144112351 is a prime.

It is a super-2 number, since 2×211221215² = 89228803332152450, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211221193 and 211221202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37937 + ... + 43146.

It is an arithmetic number, because the mean of its divisors is an integer number (31744386).

Almost surely, 2^211221215 is an apocalyptic number.

211221215 is a deficient number, since it is larger than the sum of its proper divisors (42733873).

211221215 is an equidigital number, since it uses as much as digits as its factorization.

211221215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81609.

The product of its digits is 80, while the sum is 17.

The square root of 211221215 is about 14533.4515859103. The cubic root of 211221215 is about 595.5421605454.

Adding to 211221215 its reverse (512122112), we get a palindrome (723343327).

The spelling of 211221215 in words is "two hundred eleven million, two hundred twenty-one thousand, two hundred fifteen".