21001200220121 has 16 divisors (see below), whose sum is σ = 23376849065280. Its totient is φ = 18704347696320.

The previous prime is 21001200220103. The next prime is 21001200220129. The reversal of 21001200220121 is 12102200210012.

It is a de Polignac number, because none of the positive numbers 2^k-21001200220121 is a prime.

It is a super-2 number, since 2×21001200220121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001200220096 and 21001200220105.

It is not an unprimeable number, because it can be changed into a prime (21001200220129) 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 15 ways as a sum of consecutive naturals, for example, 25972706 + ... + 26769083.

It is an arithmetic number, because the mean of its divisors is an integer number (1461053066580).

Almost surely, 2^{21001200220121} is an apocalyptic number.

It is an amenable number.

21001200220121 is a deficient number, since it is larger than the sum of its proper divisors (2375648845159).

21001200220121 is a wasteful number, since it uses less digits than its factorization.

21001200220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52742536.

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

Adding to 21001200220121 its reverse (12102200210012), we get a palindrome (33103400430133).

The spelling of 21001200220121 in words is "twenty-one trillion, one billion, two hundred million, two hundred twenty thousand, one hundred twenty-one".