21201012110021 has 32 divisors (see below), whose sum is σ = 23228513648640. Its totient is φ = 19271700953856.

The previous prime is 21201012109999. The next prime is 21201012110077. The reversal of 21201012110021 is 12001121010212.

It is a cyclic number.

It is not a de Polignac number, because 21201012110021 - 2¹⁸ = 21201011847877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201012109978 and 21201012110005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201012610021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 117756956 + ... + 117936858.

It is an arithmetic number, because the mean of its divisors is an integer number (725891051520).

Almost surely, 2^{21201012110021} is an apocalyptic number.

It is an amenable number.

21201012110021 is a deficient number, since it is larger than the sum of its proper divisors (2027501538619).

21201012110021 is a wasteful number, since it uses less digits than its factorization.

21201012110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181913.

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

Adding to 21201012110021 its reverse (12001121010212), we get a palindrome (33202133120233).

The spelling of 21201012110021 in words is "twenty-one trillion, two hundred one billion, twelve million, one hundred ten thousand, twenty-one".