20101220001221 has 4 divisors (see below), whose sum is σ = 20103577371072. Its totient is φ = 20098862631372.

The previous prime is 20101220001211. The next prime is 20101220001257. The reversal of 20101220001221 is 12210002210102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20101220001221 - 2¹⁸ = 20101219739077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20101220001196 and 20101220001205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101220001211) 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, 1178672135 + ... + 1178689188.

It is an arithmetic number, because the mean of its divisors is an integer number (5025894342768).

Almost surely, 2^{20101220001221} is an apocalyptic number.

It is an amenable number.

20101220001221 is a deficient number, since it is larger than the sum of its proper divisors (2357369851).

20101220001221 is an equidigital number, since it uses as much as digits as its factorization.

20101220001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357369850.

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

Adding to 20101220001221 its reverse (12210002210102), we get a palindrome (32311222211323).

The spelling of 20101220001221 in words is "twenty trillion, one hundred one billion, two hundred twenty million, one thousand, two hundred twenty-one".