21102111012021 has 16 divisors (see below), whose sum is σ = 30301034366400. Its totient is φ = 12985671352320.

The previous prime is 21102111012011. The next prime is 21102111012127. The reversal of 21102111012021 is 12021011120112.

It is a happy number.

It is not a de Polignac number, because 21102111012021 - 2²² = 21102106817717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102111012001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2943820 + ... + 7132341.

It is an arithmetic number, because the mean of its divisors is an integer number (1893814647900).

Almost surely, 2^{21102111012021} is an apocalyptic number.

It is an amenable number.

21102111012021 is a deficient number, since it is larger than the sum of its proper divisors (9198923354379).

21102111012021 is a wasteful number, since it uses less digits than its factorization.

21102111012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10129876.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21102111012021 its reverse (12021011120112), we get a palindrome (33123122132133).

The spelling of 21102111012021 in words is "twenty-one trillion, one hundred two billion, one hundred eleven million, twelve thousand, twenty-one".