211220201221 has 8 divisors (see below), whose sum is σ = 214104497400. Its totient is φ = 208351454400.

The previous prime is 211220201147. The next prime is 211220201251. The reversal of 211220201221 is 122102022112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 328008321 + 210892192900 = 18111^2 + 459230^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 211220201221 - 2²³ = 211211812613 is a prime.

It is a super-2 number, since 2×211220201221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211220201195 and 211220201204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211220201251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3859986 + ... + 3914323.

It is an arithmetic number, because the mean of its divisors is an integer number (26763062175).

Almost surely, 2^211220201221 is an apocalyptic number.

It is an amenable number.

211220201221 is a deficient number, since it is larger than the sum of its proper divisors (2884296179).

211220201221 is a wasteful number, since it uses less digits than its factorization.

211220201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7774679.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 211220201221 its reverse (122102022112), we get a palindrome (333322223333).

The spelling of 211220201221 in words is "two hundred eleven billion, two hundred twenty million, two hundred one thousand, two hundred twenty-one".