21121100120201 has 4 divisors (see below), whose sum is σ = 21141950170692. Its totient is φ = 21100250069712.

The previous prime is 21121100120173. The next prime is 21121100120207. The reversal of 21121100120201 is 10202100112112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10152921913225 + 10968178206976 = 3186365^2 + 3311824^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121100120201 is a prime.

It is a super-2 number, since 2×21121100120201² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121100120207) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10425023726 + ... + 10425025751.

It is an arithmetic number, because the mean of its divisors is an integer number (5285487542673).

Almost surely, 2^{21121100120201} is an apocalyptic number.

It is an amenable number.

21121100120201 is a deficient number, since it is larger than the sum of its proper divisors (20850050491).

21121100120201 is a wasteful number, since it uses less digits than its factorization.

21121100120201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20850050490.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21121100120201 its reverse (10202100112112), we get a palindrome (31323200232313).

The spelling of 21121100120201 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred million, one hundred twenty thousand, two hundred one".