21001533211 has 4 divisors (see below), whose sum is σ = 21002553400. Its totient is φ = 21000513024.

The previous prime is 21001533209. The next prime is 21001533233. The reversal of 21001533211 is 11233510012.

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 21001533211 - 2¹ = 21001533209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001533281) 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, 478566 + ... + 520603.

It is an arithmetic number, because the mean of its divisors is an integer number (5250638350).

Almost surely, 2^21001533211 is an apocalyptic number.

21001533211 is a deficient number, since it is larger than the sum of its proper divisors (1020189).

21001533211 is an equidigital number, since it uses as much as digits as its factorization.

21001533211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020188.

The product of its (nonzero) digits is 180, while the sum is 19.

The spelling of 21001533211 in words is "twenty-one billion, one million, five hundred thirty-three thousand, two hundred eleven".