21001111201 has 4 divisors (see below), whose sum is σ = 24001269952. Its totient is φ = 18000952452.

The previous prime is 21001111189. The next prime is 21001111247. The reversal of 21001111201 is 10211110012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21001111201 - 2¹⁷ = 21000980129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001111501) 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, 1500079365 + ... + 1500079378.

It is an arithmetic number, because the mean of its divisors is an integer number (6000317488).

Almost surely, 2^21001111201 is an apocalyptic number.

It is an amenable number.

21001111201 is a deficient number, since it is larger than the sum of its proper divisors (3000158751).

21001111201 is an equidigital number, since it uses as much as digits as its factorization.

21001111201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3000158750.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21001111201 its reverse (10211110012), we get a palindrome (31212221213).

The spelling of 21001111201 in words is "twenty-one billion, one million, one hundred eleven thousand, two hundred one".