20122220221 has 4 divisors (see below), whose sum is σ = 21305880252. Its totient is φ = 18938560192.

The previous prime is 20122220201. The next prime is 20122220257. The reversal of 20122220221 is 12202222102.

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 18825212025 + 1297008196 = 137205^2 + 36014^2 .

It is a cyclic number.

It is not a de Polignac number, because 20122220221 - 2⁵ = 20122220189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20122220195 and 20122220204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20122220201) 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, 591829990 + ... + 591830023.

It is an arithmetic number, because the mean of its divisors is an integer number (5326470063).

Almost surely, 2^20122220221 is an apocalyptic number.

It is an amenable number.

20122220221 is a deficient number, since it is larger than the sum of its proper divisors (1183660031).

20122220221 is a wasteful number, since it uses less digits than its factorization.

20122220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1183660030.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 20122220221 its reverse (12202222102), we get a palindrome (32324442323).

The spelling of 20122220221 in words is "twenty billion, one hundred twenty-two million, two hundred twenty thousand, two hundred twenty-one".