21153004433 has 4 divisors (see below), whose sum is σ = 23076004848. Its totient is φ = 19230004020.

The previous prime is 21153004427. The next prime is 21153004447. The reversal of 21153004433 is 33440035112.

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 21153004433 - 2⁸ = 21153004177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21153004933) 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, 961500191 + ... + 961500212.

It is an arithmetic number, because the mean of its divisors is an integer number (5769001212).

Almost surely, 2^21153004433 is an apocalyptic number.

It is an amenable number.

21153004433 is a deficient number, since it is larger than the sum of its proper divisors (1923000415).

21153004433 is a wasteful number, since it uses less digits than its factorization.

21153004433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1923000414.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 21153004433 its reverse (33440035112), we get a palindrome (54593039545).

The spelling of 21153004433 in words is "twenty-one billion, one hundred fifty-three million, four thousand, four hundred thirty-three".