21212022005 has 8 divisors (see below), whose sum is σ = 25469227224. Its totient is φ = 16959750400.

The previous prime is 21212021959. The next prime is 21212022019. The reversal of 21212022005 is 50022021212.

It can be written as a sum of positive squares in 4 ways, for example, as 4187513521 + 17024508484 = 64711^2 + 130478^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21212022005 - 2¹⁰ = 21212020981 is a prime.

It is a super-4 number, since 4×21212022005⁴ (a number of 42 digits) contains 4444 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1223936 + ... + 1241145.

It is an arithmetic number, because the mean of its divisors is an integer number (3183653403).

Almost surely, 2^21212022005 is an apocalyptic number.

It is an amenable number.

21212022005 is a deficient number, since it is larger than the sum of its proper divisors (4257205219).

21212022005 is a wasteful number, since it uses less digits than its factorization.

21212022005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2466807.

The product of its (nonzero) digits is 160, while the sum is 17.

Adding to 21212022005 its reverse (50022021212), we get a palindrome (71234043217).

The spelling of 21212022005 in words is "twenty-one billion, two hundred twelve million, twenty-two thousand, five".