221210212021 has 16 divisors (see below), whose sum is σ = 245090216448. Its totient is φ = 198721728000.

The previous prime is 221210212007. The next prime is 221210212031. The reversal of 221210212021 is 120212012122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221210212021 - 2²³ = 221201823413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221210211986 and 221210212004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221210212031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2836555 + ... + 2913496.

It is an arithmetic number, because the mean of its divisors is an integer number (15318138528).

Almost surely, 2^221210212021 is an apocalyptic number.

It is an amenable number.

221210212021 is a deficient number, since it is larger than the sum of its proper divisors (23880004427).

221210212021 is a wasteful number, since it uses less digits than its factorization.

221210212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5750172.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221210212021 its reverse (120212012122), we get a palindrome (341422224143).

The spelling of 221210212021 in words is "two hundred twenty-one billion, two hundred ten million, two hundred twelve thousand, twenty-one".