21210220112021 has 16 divisors (see below), whose sum is σ = 21712019197440. Its totient is φ = 20716078322160.

The previous prime is 21210220111973. The next prime is 21210220112033. The reversal of 21210220112021 is 12021102201212.

It is a cyclic number.

It is not a de Polignac number, because 21210220112021 - 2⁴² = 16812173600917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210220112051) 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, 2622551 + ... + 7021268.

It is an arithmetic number, because the mean of its divisors is an integer number (1357001199840).

Almost surely, 2^{21210220112021} is an apocalyptic number.

It is an amenable number.

21210220112021 is a deficient number, since it is larger than the sum of its proper divisors (501799085419).

21210220112021 is a wasteful number, since it uses less digits than its factorization.

21210220112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9644216.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21210220112021 its reverse (12021102201212), we get a palindrome (33231322313233).

The spelling of 21210220112021 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, one hundred twelve thousand, twenty-one".