21001145233 has 16 divisors (see below), whose sum is σ = 22261662720. Its totient is φ = 19770753024.

The previous prime is 21001145183. The next prime is 21001145239. The reversal of 21001145233 is 33254110012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21001145233 - 2²⁵ = 20967590801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001145239) 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, 791185 + ... + 817297.

It is an arithmetic number, because the mean of its divisors is an integer number (1391353920).

Almost surely, 2^21001145233 is an apocalyptic number.

21001145233 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21001145233 is a deficient number, since it is larger than the sum of its proper divisors (1260517487).

21001145233 is a wasteful number, since it uses less digits than its factorization.

21001145233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26688.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21001145233 its reverse (33254110012), we get a palindrome (54255255245).

The spelling of 21001145233 in words is "twenty-one billion, one million, one hundred forty-five thousand, two hundred thirty-three".