21002031211 has 4 divisors (see below), whose sum is σ = 24002321392. Its totient is φ = 18001741032.

The previous prime is 21002031191. The next prime is 21002031221. The reversal of 21002031211 is 11213020012.

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

It is a cyclic number.

It is not a de Polignac number, because 21002031211 - 2¹⁵ = 21001998443 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002031191 and 21002031200.

It is not an unprimeable number, because it can be changed into a prime (21002031221) 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 3 ways as a sum of consecutive naturals, for example, 1500145080 + ... + 1500145093.

It is an arithmetic number, because the mean of its divisors is an integer number (6000580348).

Almost surely, 2^21002031211 is an apocalyptic number.

21002031211 is a deficient number, since it is larger than the sum of its proper divisors (3000290181).

21002031211 is an equidigital number, since it uses as much as digits as its factorization.

21002031211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000290180.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21002031211 its reverse (11213020012), we get a palindrome (32215051223).

The spelling of 21002031211 in words is "twenty-one billion, two million, thirty-one thousand, two hundred eleven".