11201000001221 has 16 divisors (see below), whose sum is σ = 12194312099760. Its totient is φ = 10246758481920.

The previous prime is 11201000001199. The next prime is 11201000001239. The reversal of 11201000001221 is 12210000010211.

It can be written as a sum of positive squares in 8 ways, for example, as 5051319180196 + 6149680821025 = 2247514^2 + 2479855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11201000001221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11201000001281) 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, 29682956 + ... + 30057941.

It is an arithmetic number, because the mean of its divisors is an integer number (762144506235).

Almost surely, 2^{11201000001221} is an apocalyptic number.

It is an amenable number.

11201000001221 is a deficient number, since it is larger than the sum of its proper divisors (993312098539).

11201000001221 is a wasteful number, since it uses less digits than its factorization.

11201000001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59741224.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 11201000001221 its reverse (12210000010211), we get a palindrome (23411000011432).

The spelling of 11201000001221 in words is "eleven trillion, two hundred one billion, one thousand, two hundred twenty-one".