211020220121 has 4 divisors (see below), whose sum is σ = 211023742644. Its totient is φ = 211016697600.

The previous prime is 211020220109. The next prime is 211020220127. The reversal of 211020220121 is 121022020112.

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 395214400 + 210625005721 = 19880^2 + 458939^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211020220121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211020220096 and 211020220105.

It is not an unprimeable number, because it can be changed into a prime (211020220127) 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, 1669820 + ... + 1791741.

It is an arithmetic number, because the mean of its divisors is an integer number (52755935661).

Almost surely, 2^211020220121 is an apocalyptic number.

It is an amenable number.

211020220121 is a deficient number, since it is larger than the sum of its proper divisors (3522523).

211020220121 is an equidigital number, since it uses as much as digits as its factorization.

211020220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522522.

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

Adding to 211020220121 its reverse (121022020112), we get a palindrome (332042240233).

Subtracting from 211020220121 its reverse (121022020112), we obtain a square (89998200009 = 299997²).

The spelling of 211020220121 in words is "two hundred eleven billion, twenty million, two hundred twenty thousand, one hundred twenty-one".