221211100021 has 8 divisors (see below), whose sum is σ = 222226264064. Its totient is φ = 220196143440.

The previous prime is 221211100009. The next prime is 221211100051. The reversal of 221211100021 is 120001112122.

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

It is a cyclic number.

It is not a de Polignac number, because 221211100021 - 2⁹ = 221211099509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221211099974 and 221211100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221211100001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2336791 + ... + 2429611.

It is an arithmetic number, because the mean of its divisors is an integer number (27778283008).

Almost surely, 2^221211100021 is an apocalyptic number.

It is an amenable number.

221211100021 is a deficient number, since it is larger than the sum of its proper divisors (1015164043).

221211100021 is a wasteful number, since it uses less digits than its factorization.

221211100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103731.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 221211100021 its reverse (120001112122), we get a palindrome (341212212143).

The spelling of 221211100021 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred thousand, twenty-one".