20011212221 has 32 divisors (see below), whose sum is σ = 26883284736. Its totient is φ = 14385600000.

The previous prime is 20011212197. The next prime is 20011212241. The reversal of 20011212221 is 12221211002.

It is a cyclic number.

It is not a de Polignac number, because 20011212221 - 2¹⁴ = 20011195837 is a prime.

It is a super-2 number, since 2×20011212221² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20011212196 and 20011212205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011212241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2218721 + ... + 2227721.

It is an arithmetic number, because the mean of its divisors is an integer number (840102648).

Almost surely, 2^20011212221 is an apocalyptic number.

It is an amenable number.

20011212221 is a deficient number, since it is larger than the sum of its proper divisors (6872072515).

20011212221 is a wasteful number, since it uses less digits than its factorization.

20011212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11253.

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

Adding to 20011212221 its reverse (12221211002), we get a palindrome (32232423223).

It can be divided in two parts, 20011 and 212221, that added together give a palindrome (232232).

The spelling of 20011212221 in words is "twenty billion, eleven million, two hundred twelve thousand, two hundred twenty-one".