21000121303021 has 16 divisors (see below), whose sum is σ = 24112394309376. Its totient is φ = 17916021927936.

The previous prime is 21000121303019. The next prime is 21000121303039. The reversal of 21000121303021 is 12030312100012.

It is a cyclic number.

It is not a de Polignac number, because 21000121303021 - 2¹ = 21000121303019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000121302986 and 21000121303004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000121303081) 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, 2273241 + ... + 6867886.

It is an arithmetic number, because the mean of its divisors is an integer number (1507024644336).

Almost surely, 2^{21000121303021} is an apocalyptic number.

It is an amenable number.

21000121303021 is a deficient number, since it is larger than the sum of its proper divisors (3112273006355).

21000121303021 is a wasteful number, since it uses less digits than its factorization.

21000121303021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9142668.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21000121303021 its reverse (12030312100012), we get a palindrome (33030433403033).

The spelling of 21000121303021 in words is "twenty-one trillion, one hundred twenty-one million, three hundred three thousand, twenty-one".