20122221 has 16 divisors (see below), whose sum is σ = 30731904. Its totient is φ = 11472384.

The previous prime is 20122213. The next prime is 20122241. The reversal of 20122221 is 12222102.

It is not a de Polignac number, because 20122221 - 2³ = 20122213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20122197 and 20122206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20122241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12181 + ... + 13733.

It is an arithmetic number, because the mean of its divisors is an integer number (1920744).

Almost surely, 2^20122221 is an apocalyptic number.

20122221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20122221 is a deficient number, since it is larger than the sum of its proper divisors (10609683).

20122221 is a wasteful number, since it uses less digits than its factorization.

20122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2180.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 20122221 is about 4485.7798653077. The cubic root of 20122221 is about 271.9935705300.

Adding to 20122221 its reverse (12222102), we get a palindrome (32344323).

It can be divided in two parts, 201 and 22221, that added together give a palindrome (22422).

The spelling of 20122221 in words is "twenty million, one hundred twenty-two thousand, two hundred twenty-one".