21212100101 has 4 divisors (see below), whose sum is σ = 21212678400. Its totient is φ = 21211521804.

The previous prime is 21212100097. The next prime is 21212100121. The reversal of 21212100101 is 10100121212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21212100101 - 2² = 21212100097 is a prime.

It is a super-3 number, since 3×21212100101³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212100121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230111 + ... + 308828.

It is an arithmetic number, because the mean of its divisors is an integer number (5303169600).

Almost surely, 2^21212100101 is an apocalyptic number.

It is an amenable number.

21212100101 is a deficient number, since it is larger than the sum of its proper divisors (578299).

21212100101 is an equidigital number, since it uses as much as digits as its factorization.

21212100101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578298.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21212100101 its reverse (10100121212), we get a palindrome (31312221313).

The spelling of 21212100101 in words is "twenty-one billion, two hundred twelve million, one hundred thousand, one hundred one".