21212102001 has 16 divisors (see below), whose sum is σ = 28355133248. Its totient is φ = 14105275200.

The previous prime is 21212101973. The next prime is 21212102003. The reversal of 21212102001 is 10020121212.

It is not a de Polignac number, because 21212102001 - 2¹³ = 21212093809 is a prime.

It is a super-3 number, since 3×21212102001³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212102003) 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, 2821890 + ... + 2829396.

It is an arithmetic number, because the mean of its divisors is an integer number (1772195828).

Almost surely, 2^21212102001 is an apocalyptic number.

It is an amenable number.

21212102001 is a deficient number, since it is larger than the sum of its proper divisors (7143031247).

21212102001 is a wasteful number, since it uses less digits than its factorization.

21212102001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9792.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21212102001 its reverse (10020121212), we get a palindrome (31232223213).

The spelling of 21212102001 in words is "twenty-one billion, two hundred twelve million, one hundred two thousand, one".