20001112001221 has 8 divisors (see below), whose sum is σ = 21539803174904. Its totient is φ = 18462441412800.

The previous prime is 20001112001203. The next prime is 20001112001239. The reversal of 20001112001221 is 12210021110002.

It is an interprime number because it is at equal distance from previous prime (20001112001203) and next prime (20001112001239).

It can be written as a sum of positive squares in 4 ways, for example, as 3570168681121 + 16430943320100 = 1889489^2 + 4053510^2 .

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 20001112001221 - 2²⁹ = 20000575130309 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001112001201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3098130 + ... + 7042771.

It is an arithmetic number, because the mean of its divisors is an integer number (2692475396863).

Almost surely, 2^{20001112001221} is an apocalyptic number.

It is an amenable number.

20001112001221 is a deficient number, since it is larger than the sum of its proper divisors (1538691173683).

20001112001221 is a wasteful number, since it uses less digits than its factorization.

20001112001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10292631.

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

Adding to 20001112001221 its reverse (12210021110002), we get a palindrome (32211133111223).

The spelling of 20001112001221 in words is "twenty trillion, one billion, one hundred twelve million, one thousand, two hundred twenty-one".