21531200433 has 4 divisors (see below), whose sum is σ = 28708267248. Its totient is φ = 14354133620.

The previous prime is 21531200419. The next prime is 21531200437. The reversal of 21531200433 is 33400213512.

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 21531200433 - 2⁵ = 21531200401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21531200437) 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, 3588533403 + ... + 3588533408.

It is an arithmetic number, because the mean of its divisors is an integer number (7177066812).

Almost surely, 2^21531200433 is an apocalyptic number.

It is an amenable number.

21531200433 is a deficient number, since it is larger than the sum of its proper divisors (7177066815).

21531200433 is an equidigital number, since it uses as much as digits as its factorization.

21531200433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7177066814.

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21531200433 its reverse (33400213512), we get a palindrome (54931413945).

The spelling of 21531200433 in words is "twenty-one billion, five hundred thirty-one million, two hundred thousand, four hundred thirty-three".