21203553443 has 8 divisors (see below), whose sum is σ = 22406381520. Its totient is φ = 20009410560.

The previous prime is 21203553419. The next prime is 21203553509. The reversal of 21203553443 is 34435530212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21203553443 - 2⁶ = 21203553379 is a prime.

It is a super-2 number, since 2×21203553443² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203553643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2166278 + ... + 2176043.

It is an arithmetic number, because the mean of its divisors is an integer number (2800797690).

Almost surely, 2^21203553443 is an apocalyptic number.

21203553443 is a deficient number, since it is larger than the sum of its proper divisors (1202828077).

21203553443 is a wasteful number, since it uses less digits than its factorization.

21203553443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4342597.

The product of its (nonzero) digits is 43200, while the sum is 32.

The spelling of 21203553443 in words is "twenty-one billion, two hundred three million, five hundred fifty-three thousand, four hundred forty-three".