21204411040243 has 16 divisors (see below), whose sum is σ = 22331855838240. Its totient is φ = 20078110483200.

The previous prime is 21204411040231. The next prime is 21204411040283. The reversal of 21204411040243 is 34204011440212.

It is a cyclic number.

It is not a de Polignac number, because 21204411040243 - 2³³ = 21195821105651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21204411040283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 532473273 + ... + 532513093.

It is an arithmetic number, because the mean of its divisors is an integer number (1395740989890).

Almost surely, 2^{21204411040243} is an apocalyptic number.

21204411040243 is a deficient number, since it is larger than the sum of its proper divisors (1127444797997).

21204411040243 is a wasteful number, since it uses less digits than its factorization.

21204411040243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53478.

The product of its (nonzero) digits is 6144, while the sum is 28.

Adding to 21204411040243 its reverse (34204011440212), we get a palindrome (55408422480455).

The spelling of 21204411040243 in words is "twenty-one trillion, two hundred four billion, four hundred eleven million, forty thousand, two hundred forty-three".