21210102011 has 4 divisors (see below), whose sum is σ = 24240116592. Its totient is φ = 18180087432.

The previous prime is 21210102007. The next prime is 21210102019. The reversal of 21210102011 is 11020101212.

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

It is a cyclic number.

It is not a de Polignac number, because 21210102011 - 2² = 21210102007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210101983 and 21210102001.

It is not an unprimeable number, because it can be changed into a prime (21210102019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1515007280 + ... + 1515007293.

It is an arithmetic number, because the mean of its divisors is an integer number (6060029148).

Almost surely, 2^21210102011 is an apocalyptic number.

21210102011 is a deficient number, since it is larger than the sum of its proper divisors (3030014581).

21210102011 is an equidigital number, since it uses as much as digits as its factorization.

21210102011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030014580.

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

Adding to 21210102011 its reverse (11020101212), we get a palindrome (32230203223).

The spelling of 21210102011 in words is "twenty-one billion, two hundred ten million, one hundred two thousand, eleven".