21220120220021 has 8 divisors (see below), whose sum is σ = 21957214514400. Its totient is φ = 20483383659760.

The previous prime is 21220120220017. The next prime is 21220120220077. The reversal of 21220120220021 is 12002202102212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21220120220021 - 2² = 21220120220017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220120220081) 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 7 ways as a sum of consecutive naturals, for example, 89312831 + ... + 89550108.

It is an arithmetic number, because the mean of its divisors is an integer number (2744651814300).

Almost surely, 2^{21220120220021} is an apocalyptic number.

It is an amenable number.

21220120220021 is a deficient number, since it is larger than the sum of its proper divisors (737094294379).

21220120220021 is a wasteful number, since it uses less digits than its factorization.

21220120220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178867059.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21220120220021 its reverse (12002202102212), we get a palindrome (33222322322233).

The spelling of 21220120220021 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty million, two hundred twenty thousand, twenty-one".