21001010211 has 10 divisors (see below), whose sum is σ = 31371879572. Its totient is φ = 14000673420.

The previous prime is 21001010179. The next prime is 21001010237. The reversal of 21001010211 is 11201010012.

It is a happy number.

It is not a de Polignac number, because 21001010211 - 2⁵ = 21001010179 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001010193 and 21001010202.

It is not an unprimeable number, because it can be changed into a prime (21001017211) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 129635785 + ... + 129635946.

Almost surely, 2^21001010211 is an apocalyptic number.

21001010211 is a deficient number, since it is larger than the sum of its proper divisors (10370869361).

21001010211 is an equidigital number, since it uses as much as digits as its factorization.

21001010211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259271743 (or 259271734 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21001010211 its reverse (11201010012), we get a palindrome (32202020223).

The spelling of 21001010211 in words is "twenty-one billion, one million, ten thousand, two hundred eleven".