20011220121 has 8 divisors (see below), whose sum is σ = 26683040224. Its totient is φ = 13340106720.

The previous prime is 20011220113. The next prime is 20011220153. The reversal of 20011220121 is 12102211002.

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

It is not a de Polignac number, because 20011220121 - 2³ = 20011220113 is a prime.

It is a super-2 number, since 2×20011220121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

20011220121 is a modest number, since divided by 220121 gives 20011 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 20011220097 and 20011220106.

It is not an unprimeable number, because it can be changed into a prime (20011220821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106636 + ... + 226701.

It is an arithmetic number, because the mean of its divisors is an integer number (3335380028).

Almost surely, 2^20011220121 is an apocalyptic number.

It is an amenable number.

20011220121 is a deficient number, since it is larger than the sum of its proper divisors (6671820103).

20011220121 is a wasteful number, since it uses less digits than its factorization.

20011220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353351.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20011220121 its reverse (12102211002), we get a palindrome (32113431123).

The spelling of 20011220121 in words is "twenty billion, eleven million, two hundred twenty thousand, one hundred twenty-one".