211001001221 has 4 divisors (see below), whose sum is σ = 211679461344. Its totient is φ = 210322541100.

The previous prime is 211001001199. The next prime is 211001001229. The reversal of 211001001221 is 122100100112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211001001221 - 2³⁰ = 209927259397 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 (211001001229) 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, 339229595 + ... + 339230216.

It is an arithmetic number, because the mean of its divisors is an integer number (52919865336).

Almost surely, 2^211001001221 is an apocalyptic number.

It is an amenable number.

211001001221 is a deficient number, since it is larger than the sum of its proper divisors (678460123).

211001001221 is an equidigital number, since it uses as much as digits as its factorization.

211001001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 678460122.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 211001001221 its reverse (122100100112), we get a palindrome (333101101333).

The spelling of 211001001221 in words is "two hundred eleven billion, one million, one thousand, two hundred twenty-one".