21220102010221 has 4 divisors (see below), whose sum is σ = 21234726478944. Its totient is φ = 21205477541500.

The previous prime is 21220102010209. The next prime is 21220102010249. The reversal of 21220102010221 is 12201020102212.

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-21220102010221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220102010195 and 21220102010204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220102010621) 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, 7312232185 + ... + 7312235086.

It is an arithmetic number, because the mean of its divisors is an integer number (5308681619736).

Almost surely, 2^{21220102010221} is an apocalyptic number.

It is an amenable number.

21220102010221 is a deficient number, since it is larger than the sum of its proper divisors (14624468723).

21220102010221 is a wasteful number, since it uses less digits than its factorization.

21220102010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14624468722.

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

Adding to 21220102010221 its reverse (12201020102212), we get a palindrome (33421122112433).

It can be divided in two parts, 2 and 1220102010221, that multiplied together give a palindrome (2440204020442).

The spelling of 21220102010221 in words is "twenty-one trillion, two hundred twenty billion, one hundred two million, ten thousand, two hundred twenty-one".