21710472271221 has 16 divisors (see below), whose sum is σ = 29317515944960. Its totient is φ = 14288585865840.

The previous prime is 21710472271193. The next prime is 21710472271237. The reversal of 21710472271221 is 12217227401712.

It is not a de Polignac number, because 21710472271221 - 2³¹ = 21708324787573 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 21710472271221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21710472271291) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4100335 + ... + 7761036.

It is an arithmetic number, because the mean of its divisors is an integer number (1832344746560).

Almost surely, 2^{21710472271221} is an apocalyptic number.

It is an amenable number.

21710472271221 is a deficient number, since it is larger than the sum of its proper divisors (7607043673739).

21710472271221 is a wasteful number, since it uses less digits than its factorization.

21710472271221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11869176.

The product of its (nonzero) digits is 43904, while the sum is 39.

Adding to 21710472271221 its reverse (12217227401712), we get a palindrome (33927699672933).

The spelling of 21710472271221 in words is "twenty-one trillion, seven hundred ten billion, four hundred seventy-two million, two hundred seventy-one thousand, two hundred twenty-one".