21212222001 has 8 divisors (see below), whose sum is σ = 28298484480. Its totient is φ = 14133720432.

The previous prime is 21212221993. The next prime is 21212222011. The reversal of 21212222001 is 10022221212.

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

It is not a de Polignac number, because 21212222001 - 2³ = 21212221993 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21212222011) 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, 1933846 + ... + 1944783.

It is an arithmetic number, because the mean of its divisors is an integer number (3537310560).

Almost surely, 2^21212222001 is an apocalyptic number.

It is an amenable number.

21212222001 is a deficient number, since it is larger than the sum of its proper divisors (7086262479).

21212222001 is a wasteful number, since it uses less digits than its factorization.

21212222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3880455.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21212222001 its reverse (10022221212), we get a palindrome (31234443213).

The spelling of 21212222001 in words is "twenty-one billion, two hundred twelve million, two hundred twenty-two thousand, one".