21102001212011 has 4 divisors (see below), whose sum is σ = 21111997425024. Its totient is φ = 21092004999000.

The previous prime is 21102001212001. The next prime is 21102001212013. The reversal of 21102001212011 is 11021210020112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102001212011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21102001212013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4998103340 + ... + 4998107561.

It is an arithmetic number, because the mean of its divisors is an integer number (5277999356256).

Almost surely, 2^{21102001212011} is an apocalyptic number.

21102001212011 is a deficient number, since it is larger than the sum of its proper divisors (9996213013).

21102001212011 is an equidigital number, since it uses as much as digits as its factorization.

21102001212011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9996213012.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21102001212011 its reverse (11021210020112), we get a palindrome (32123211232123).

The spelling of 21102001212011 in words is "twenty-one trillion, one hundred two billion, one million, two hundred twelve thousand, eleven".