21553555204424 has 16 divisors (see below), whose sum is σ = 40413246283500. Its totient is φ = 10776689528832.

The previous prime is 21553555204393. The next prime is 21553555204477. The reversal of 21553555204424 is 42440255535512.

It can be written as a sum of positive squares in 2 ways, for example, as 21452737524100 + 100817680324 = 4631710^2 + 317518^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9963257 + ... + 11932040.

Almost surely, 2^{21553555204424} is an apocalyptic number.

It is an amenable number.

21553555204424 is a deficient number, since it is larger than the sum of its proper divisors (18859691079076).

21553555204424 is a wasteful number, since it uses less digits than its factorization.

21553555204424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22018352 (or 22018348 counting only the distinct ones).

The product of its (nonzero) digits is 4800000, while the sum is 47.

The spelling of 21553555204424 in words is "twenty-one trillion, five hundred fifty-three billion, five hundred fifty-five million, two hundred four thousand, four hundred twenty-four".