21001033213 has 16 divisors (see below), whose sum is σ = 21460001472. Its totient is φ = 20546064000.

The previous prime is 21001033201. The next prime is 21001033217. The reversal of 21001033213 is 31233010012.

It is a cyclic number.

It is not a de Polignac number, because 21001033213 - 2²⁵ = 20967478781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001033217) 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, 18700270 + ... + 18701392.

It is an arithmetic number, because the mean of its divisors is an integer number (1341250092).

Almost surely, 2^21001033213 is an apocalyptic number.

It is an amenable number.

21001033213 is a deficient number, since it is larger than the sum of its proper divisors (458968259).

21001033213 is a wasteful number, since it uses less digits than its factorization.

21001033213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2556.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21001033213 its reverse (31233010012), we get a palindrome (52234043225).

The spelling of 21001033213 in words is "twenty-one billion, one million, thirty-three thousand, two hundred thirteen".