21211211010221 has 8 divisors (see below), whose sum is σ = 21284263799424. Its totient is φ = 21138191886240.

The previous prime is 21211211010191. The next prime is 21211211010233. The reversal of 21211211010221 is 12201011211212.

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 21211211010221 - 2²² = 21211206815917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21211211010221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211211019221) 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, 7153685 + ... + 9674586.

It is an arithmetic number, because the mean of its divisors is an integer number (2660532974928).

Almost surely, 2^{21211211010221} is an apocalyptic number.

It is an amenable number.

21211211010221 is a deficient number, since it is larger than the sum of its proper divisors (73052789203).

21211211010221 is a wasteful number, since it uses less digits than its factorization.

21211211010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16832611.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21211211010221 its reverse (12201011211212), we get a palindrome (33412222221433).

The spelling of 21211211010221 in words is "twenty-one trillion, two hundred eleven billion, two hundred eleven million, ten thousand, two hundred twenty-one".