21001221120001 has 8 divisors (see below), whose sum is σ = 21359049291360. Its totient is φ = 20643455457792.

The previous prime is 21001221119999. The next prime is 21001221120013. The reversal of 21001221120001 is 10002112210012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001221120001 - 2¹ = 21001221119999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001221120101) 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 7 ways as a sum of consecutive naturals, for example, 14949375 + ... + 16293748.

It is an arithmetic number, because the mean of its divisors is an integer number (2669881161420).

Almost surely, 2^{21001221120001} is an apocalyptic number.

It is an amenable number.

21001221120001 is a deficient number, since it is larger than the sum of its proper divisors (357828171359).

21001221120001 is a wasteful number, since it uses less digits than its factorization.

21001221120001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31254575.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001221120001 its reverse (10002112210012), we get a palindrome (31003333330013).

The spelling of 21001221120001 in words is "twenty-one trillion, one billion, two hundred twenty-one million, one hundred twenty thousand, one".