211004221 has 4 divisors (see below), whose sum is σ = 223416252. Its totient is φ = 198592192.

The previous prime is 211004207. The next prime is 211004263. The reversal of 211004221 is 122400112.

It is a happy number.

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 197964900 + 13039321 = 14070^2 + 3611^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211004221 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 (211004021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6205990 + ... + 6206023.

It is an arithmetic number, because the mean of its divisors is an integer number (55854063).

Almost surely, 2^211004221 is an apocalyptic number.

It is an amenable number.

211004221 is a deficient number, since it is larger than the sum of its proper divisors (12412031).

211004221 is a wasteful number, since it uses less digits than its factorization.

211004221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12412030.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 211004221 is about 14525.9843384192. The cubic root of 211004221 is about 595.3381511225.

Adding to 211004221 its reverse (122400112), we get a palindrome (333404333).

The spelling of 211004221 in words is "two hundred eleven million, four thousand, two hundred twenty-one".