21533502423233 has 4 divisors (see below), whose sum is σ = 21557243882160. Its totient is φ = 21509760964308.

The previous prime is 21533502423179. The next prime is 21533502423247. The reversal of 21533502423233 is 33232420533512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21533502423233 - 2⁸ = 21533502422977 is a prime.

It is a super-2 number, since 2×21533502423233² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21533502420233) 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, 11870728103 + ... + 11870729916.

It is an arithmetic number, because the mean of its divisors is an integer number (5389310970540).

Almost surely, 2^{21533502423233} is an apocalyptic number.

It is an amenable number.

21533502423233 is a deficient number, since it is larger than the sum of its proper divisors (23741458927).

21533502423233 is an equidigital number, since it uses as much as digits as its factorization.

21533502423233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23741458926.

The product of its (nonzero) digits is 388800, while the sum is 38.

Adding to 21533502423233 its reverse (33232420533512), we get a palindrome (54765922956745).

The spelling of 21533502423233 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred two million, four hundred twenty-three thousand, two hundred thirty-three".