21010102220021 has 16 divisors (see below), whose sum is σ = 22074177706560. Its totient is φ = 19970393278080.

The previous prime is 21010102219987. The next prime is 21010102220099. The reversal of 21010102220021 is 12002220101012.

It is a cyclic number.

It is not a de Polignac number, because 21010102220021 - 2¹⁸ = 21010101957877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010102219978 and 21010102220005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010102220321) 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, 14740640 + ... + 16103001.

It is an arithmetic number, because the mean of its divisors is an integer number (1379636106660).

Almost surely, 2^{21010102220021} is an apocalyptic number.

It is an amenable number.

21010102220021 is a deficient number, since it is larger than the sum of its proper divisors (1064075486539).

21010102220021 is a wasteful number, since it uses less digits than its factorization.

21010102220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30844036.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21010102220021 its reverse (12002220101012), we get a palindrome (33012322321033).

The spelling of 21010102220021 in words is "twenty-one trillion, ten billion, one hundred two million, two hundred twenty thousand, twenty-one".