21201200220021 has 16 divisors (see below), whose sum is σ = 29756684379840. Its totient is φ = 13389955464960.

The previous prime is 21201200219971. The next prime is 21201200220029. The reversal of 21201200220021 is 12002200210212.

It is not a de Polignac number, because 21201200220021 - 2⁶ = 21201200219957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201200220029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1031940 + ... + 6592973.

It is an arithmetic number, because the mean of its divisors is an integer number (1859792773740).

Almost surely, 2^{21201200220021} is an apocalyptic number.

It is an amenable number.

21201200220021 is a deficient number, since it is larger than the sum of its proper divisors (8555484159819).

21201200220021 is a wasteful number, since it uses less digits than its factorization.

21201200220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7673716.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21201200220021 its reverse (12002200210212), we get a palindrome (33203400430233).

The spelling of 21201200220021 in words is "twenty-one trillion, two hundred one billion, two hundred million, two hundred twenty thousand, twenty-one".