21012101121211 has 4 divisors (see below), whose sum is σ = 21012132758400. Its totient is φ = 21012069484024.

The previous prime is 21012101121199. The next prime is 21012101121217. The reversal of 21012101121211 is 11212110121012.

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-21012101121211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012101121217) 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, 14800516 + ... + 16157953.

It is an arithmetic number, because the mean of its divisors is an integer number (5253033189600).

Almost surely, 2^{21012101121211} is an apocalyptic number.

21012101121211 is a deficient number, since it is larger than the sum of its proper divisors (31637189).

21012101121211 is an equidigital number, since it uses as much as digits as its factorization.

21012101121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31637188.

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

Adding to 21012101121211 its reverse (11212110121012), we get a palindrome (32224211242223).

The spelling of 21012101121211 in words is "twenty-one trillion, twelve billion, one hundred one million, one hundred twenty-one thousand, two hundred eleven".