21544245210433 has 4 divisors (see below), whose sum is σ = 23502812956848. Its totient is φ = 19585677464020.

The previous prime is 21544245210377. The next prime is 21544245210451. The reversal of 21544245210433 is 33401254244512.

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 a de Polignac number, because none of the positive numbers 2^k-21544245210433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21544245210473) 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, 979283873191 + ... + 979283873212.

It is an arithmetic number, because the mean of its divisors is an integer number (5875703239212).

Almost surely, 2^{21544245210433} is an apocalyptic number.

It is an amenable number.

21544245210433 is a deficient number, since it is larger than the sum of its proper divisors (1958567746415).

21544245210433 is a wasteful number, since it uses less digits than its factorization.

21544245210433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1958567746414.

The product of its (nonzero) digits is 460800, while the sum is 40.

Adding to 21544245210433 its reverse (33401254244512), we get a palindrome (54945499454945).

The spelling of 21544245210433 in words is "twenty-one trillion, five hundred forty-four billion, two hundred forty-five million, two hundred ten thousand, four hundred thirty-three".