221021210100021 has 8 divisors (see below), whose sum is σ = 294695550703584. Its totient is φ = 147347171448240.

The previous prime is 221021210099953. The next prime is 221021210100137. The reversal of 221021210100021 is 120001012120122.

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

It is not a de Polignac number, because 221021210100021 - 2³⁸ = 220746332193077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021211100021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73774446 + ... + 76711871.

It is an arithmetic number, because the mean of its divisors is an integer number (36836943837948).

Almost surely, 2^{221021210100021} is an apocalyptic number.

It is an amenable number.

221021210100021 is a deficient number, since it is larger than the sum of its proper divisors (73674340603563).

221021210100021 is a wasteful number, since it uses less digits than its factorization.

221021210100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150975891.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221021210100021 its reverse (120001012120122), we get a palindrome (341022222220143).

The spelling of 221021210100021 in words is "two hundred twenty-one trillion, twenty-one billion, two hundred ten million, one hundred thousand, twenty-one".