21001433155441 has 4 divisors (see below), whose sum is σ = 21914538944832. Its totient is φ = 20088327366052.

The previous prime is 21001433155393. The next prime is 21001433155513. The reversal of 21001433155441 is 14455133410012.

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 21001433155441 - 2⁹ = 21001433154929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001433155397 and 21001433155406.

It is not an unprimeable number, because it can be changed into a prime (21001433156441) 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, 456552894661 + ... + 456552894706.

It is an arithmetic number, because the mean of its divisors is an integer number (5478634736208).

Almost surely, 2^{21001433155441} is an apocalyptic number.

It is an amenable number.

21001433155441 is a deficient number, since it is larger than the sum of its proper divisors (913105789391).

21001433155441 is an equidigital number, since it uses as much as digits as its factorization.

21001433155441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913105789390.

The product of its (nonzero) digits is 28800, while the sum is 34.

Adding to 21001433155441 its reverse (14455133410012), we get a palindrome (35456566565453).

The spelling of 21001433155441 in words is "twenty-one trillion, one billion, four hundred thirty-three million, one hundred fifty-five thousand, four hundred forty-one".