211221000221 has 24 divisors (see below), whose sum is σ = 267092821632. Its totient is φ = 163497708000.

The previous prime is 211221000217. The next prime is 211221000253. The reversal of 211221000221 is 122000122112.

It is not a de Polignac number, because 211221000221 - 2² = 211221000217 is a prime.

It is a super-2 number, since 2×211221000221² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211221000196 and 211221000205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221000721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 697850 + ... + 953643.

It is an arithmetic number, because the mean of its divisors is an integer number (11128867568).

Almost surely, 2^211221000221 is an apocalyptic number.

It is an amenable number.

211221000221 is a deficient number, since it is larger than the sum of its proper divisors (55871821411).

211221000221 is a wasteful number, since it uses less digits than its factorization.

211221000221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1651673 (or 1651662 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 211221000221 its reverse (122000122112), we get a palindrome (333221122333).

The spelling of 211221000221 in words is "two hundred eleven billion, two hundred twenty-one million, two hundred twenty-one", and thus it is an aban number.