221000212021 has 4 divisors (see below), whose sum is σ = 222323566752. Its totient is φ = 219676857292.

The previous prime is 221000211967. The next prime is 221000212039. The reversal of 221000212021 is 120212000122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221000212021 - 2⁷ = 221000211893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221000211992 and 221000212010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000212421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 661677115 + ... + 661677448.

It is an arithmetic number, because the mean of its divisors is an integer number (55580891688).

Almost surely, 2^221000212021 is an apocalyptic number.

It is an amenable number.

221000212021 is a deficient number, since it is larger than the sum of its proper divisors (1323354731).

221000212021 is a wasteful number, since it uses less digits than its factorization.

221000212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323354730.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221000212021 its reverse (120212000122), we get a palindrome (341212212143).

The spelling of 221000212021 in words is "two hundred twenty-one billion, two hundred twelve thousand, twenty-one".