221021221200021 has 24 divisors (see below), whose sum is σ = 349051533854400. Its totient is φ = 133653920601600.

The previous prime is 221021221200019. The next prime is 221021221200023. The reversal of 221021221200021 is 120002122120122.

It is a happy number.

221021221200021 is a `hidden beast` number, since 2 + 210 + 212 + 21 + 200 + 0 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (221021221200019) and next prime (221021221200023).

It is not a de Polignac number, because 221021221200021 - 2¹ = 221021221200019 is a prime.

It is a super-2 number, since 2×221021221200021² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221021221199967 and 221021221200003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021221200023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2486077585 + ... + 2486166486.

It is an arithmetic number, because the mean of its divisors is an integer number (14543813910600).

Almost surely, 2^{221021221200021} is an apocalyptic number.

It is an amenable number.

221021221200021 is a deficient number, since it is larger than the sum of its proper divisors (128030312654379).

221021221200021 is a wasteful number, since it uses less digits than its factorization.

221021221200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4972244537 (or 4972244534 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221021221200021 its reverse (120002122120122), we get a palindrome (341023343320143).

The spelling of 221021221200021 in words is "two hundred twenty-one trillion, twenty-one billion, two hundred twenty-one million, two hundred thousand, twenty-one".