21021011233 has 8 divisors (see below), whose sum is σ = 21130895016. Its totient is φ = 20911315200.

The previous prime is 21021011213. The next prime is 21021011239. The reversal of 21021011233 is 33211012012.

It can be written as a sum of positive squares in 4 ways, for example, as 2521747089 + 18499264144 = 50217^2 + 136012^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21021011233 - 2¹⁷ = 21020880161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021011239) 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 7 ways as a sum of consecutive naturals, for example, 180435 + ... + 273127.

It is an arithmetic number, because the mean of its divisors is an integer number (2641361877).

Almost surely, 2^21021011233 is an apocalyptic number.

It is an amenable number.

21021011233 is a deficient number, since it is larger than the sum of its proper divisors (109883783).

21021011233 is an equidigital number, since it uses as much as digits as its factorization.

21021011233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93875.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21021011233 its reverse (33211012012), we get a palindrome (54232023245).

The spelling of 21021011233 in words is "twenty-one billion, twenty-one million, eleven thousand, two hundred thirty-three".