221001020100021 has 16 divisors (see below), whose sum is σ = 337172649334784. Its totient is φ = 126132850899504.

The previous prime is 221001020100013. The next prime is 221001020100041. The reversal of 221001020100021 is 120001020100122.

It is not a de Polignac number, because 221001020100021 - 2³ = 221001020100013 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 (221001020100041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6393578161 + ... + 6393612726.

It is an arithmetic number, because the mean of its divisors is an integer number (21073290583424).

Almost surely, 2^{221001020100021} is an apocalyptic number.

221001020100021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221001020100021 is a deficient number, since it is larger than the sum of its proper divisors (116171629234763).

221001020100021 is a wasteful number, since it uses less digits than its factorization.

221001020100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12787191720.

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

Adding to 221001020100021 its reverse (120001020100122), we get a palindrome (341002040200143).

The spelling of 221001020100021 in words is "two hundred twenty-one trillion, one billion, twenty million, one hundred thousand, twenty-one".