21433340553 has 4 divisors (see below), whose sum is σ = 28577787408. Its totient is φ = 14288893700.

The previous prime is 21433340521. The next prime is 21433340557. The reversal of 21433340553 is 35504333412.

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 21433340553 - 2⁵ = 21433340521 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21433340557) 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, 3572223423 + ... + 3572223428.

It is an arithmetic number, because the mean of its divisors is an integer number (7144446852).

Almost surely, 2^21433340553 is an apocalyptic number.

It is an amenable number.

21433340553 is a deficient number, since it is larger than the sum of its proper divisors (7144446855).

21433340553 is an equidigital number, since it uses as much as digits as its factorization.

21433340553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7144446854.

The product of its (nonzero) digits is 64800, while the sum is 33.

Adding to 21433340553 its reverse (35504333412), we get a palindrome (56937673965).

The spelling of 21433340553 in words is "twenty-one billion, four hundred thirty-three million, three hundred forty thousand, five hundred fifty-three".