21212022017 has 16 divisors (see below), whose sum is σ = 22808915712. Its totient is φ = 19656268800.

The previous prime is 21212021959. The next prime is 21212022019. The reversal of 21212022017 is 71022021212.

It is a cyclic number.

It is not a de Polignac number, because 21212022017 - 2²⁴ = 21195244801 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 21212022017.

It is not an unprimeable number, because it can be changed into a prime (21212022019) 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, 253508 + ... + 326634.

It is an arithmetic number, because the mean of its divisors is an integer number (1425557232).

Almost surely, 2^21212022017 is an apocalyptic number.

It is an amenable number.

21212022017 is a deficient number, since it is larger than the sum of its proper divisors (1596893695).

21212022017 is a wasteful number, since it uses less digits than its factorization.

21212022017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73408.

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 21212022017 its reverse (71022021212), we get a palindrome (92234043229).

The spelling of 21212022017 in words is "twenty-one billion, two hundred twelve million, twenty-two thousand, seventeen".