221210020021 has 4 divisors (see below), whose sum is σ = 221793688000. Its totient is φ = 220626352044.

The previous prime is 221210019949. The next prime is 221210020049. The reversal of 221210020021 is 120020012122.

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 a de Polignac number, because none of the positive numbers 2^k-221210020021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221210019983 and 221210020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221210020121) 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, 291833421 + ... + 291834178.

It is an arithmetic number, because the mean of its divisors is an integer number (55448422000).

Almost surely, 2^221210020021 is an apocalyptic number.

It is an amenable number.

221210020021 is a deficient number, since it is larger than the sum of its proper divisors (583667979).

221210020021 is an equidigital number, since it uses as much as digits as its factorization.

221210020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583667978.

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

Adding to 221210020021 its reverse (120020012122), we get a palindrome (341230032143).

The spelling of 221210020021 in words is "two hundred twenty-one billion, two hundred ten million, twenty thousand, twenty-one".