20121100101221 has 16 divisors (see below), whose sum is σ = 23002888083840. Its totient is φ = 17241149123520.

The previous prime is 20121100101197. The next prime is 20121100101229. The reversal of 20121100101221 is 12210100112102.

It is a de Polignac number, because none of the positive numbers 2^k-20121100101221 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20121100101196 and 20121100101205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121100101229) 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, 517352186 + ... + 517391076.

It is an arithmetic number, because the mean of its divisors is an integer number (1437680505240).

Almost surely, 2^{20121100101221} is an apocalyptic number.

It is an amenable number.

20121100101221 is a deficient number, since it is larger than the sum of its proper divisors (2881787982619).

20121100101221 is a wasteful number, since it uses less digits than its factorization.

20121100101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60604.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20121100101221 its reverse (12210100112102), we get a palindrome (32331200213323).

The spelling of 20121100101221 in words is "twenty trillion, one hundred twenty-one billion, one hundred million, one hundred one thousand, two hundred twenty-one".