20121223220021 has 64 divisors (see below), whose sum is σ = 26447453683200. Its totient is φ = 14850099532800.

The previous prime is 20121223220017. The next prime is 20121223220023. The reversal of 20121223220021 is 12002232212102.

It is not a de Polignac number, because 20121223220021 - 2² = 20121223220017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121223219975 and 20121223220002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121223220023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 50609435 + ... + 51005463.

It is an arithmetic number, because the mean of its divisors is an integer number (413241463800).

Almost surely, 2^{20121223220021} is an apocalyptic number.

It is an amenable number.

20121223220021 is a deficient number, since it is larger than the sum of its proper divisors (6326230463179).

20121223220021 is a wasteful number, since it uses less digits than its factorization.

20121223220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396510.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 20121223220021 its reverse (12002232212102), we get a palindrome (32123455432123).

The spelling of 20121223220021 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-three million, two hundred twenty thousand, twenty-one".