21235443533 has 4 divisors (see below), whose sum is σ = 21239359008. Its totient is φ = 21231528060.

The previous prime is 21235443451. The next prime is 21235443539. The reversal of 21235443533 is 33534453212.

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 21235443533 - 2⁸ = 21235443277 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21235443493 and 21235443502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235443539) 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, 1949591 + ... + 1960452.

It is an arithmetic number, because the mean of its divisors is an integer number (5309839752).

Almost surely, 2^21235443533 is an apocalyptic number.

It is an amenable number.

21235443533 is a deficient number, since it is larger than the sum of its proper divisors (3915475).

21235443533 is an equidigital number, since it uses as much as digits as its factorization.

21235443533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3915474.

The product of its digits is 129600, while the sum is 35.

Adding to 21235443533 its reverse (33534453212), we get a palindrome (54769896745).

The spelling of 21235443533 in words is "twenty-one billion, two hundred thirty-five million, four hundred forty-three thousand, five hundred thirty-three".