21012202111 has 4 divisors (see below), whose sum is σ = 21027574512. Its totient is φ = 20996829712.

The previous prime is 21012202091. The next prime is 21012202117. The reversal of 21012202111 is 11120221012.

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 21012202111 - 2⁹ = 21012201599 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012202091 and 21012202100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012202117) 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, 7684150 + ... + 7686883.

It is an arithmetic number, because the mean of its divisors is an integer number (5256893628).

Almost surely, 2^21012202111 is an apocalyptic number.

21012202111 is a deficient number, since it is larger than the sum of its proper divisors (15372401).

21012202111 is a wasteful number, since it uses less digits than its factorization.

21012202111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15372400.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012202111 its reverse (11120221012), we get a palindrome (32132423123).

The spelling of 21012202111 in words is "twenty-one billion, twelve million, two hundred two thousand, one hundred eleven".