21503055504321 has 48 divisors (see below), whose sum is σ = 32395711315968. Its totient is φ = 14252946786000.

The previous prime is 21503055504257. The next prime is 21503055504401. The reversal of 21503055504321 is 12340555030512.

21503055504321 is a `hidden beast` number, since 2 + 1 + 50 + 30 + 5 + 550 + 4 + 3 + 21 = 666.

It is not a de Polignac number, because 21503055504321 - 2⁶ = 21503055504257 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21503055504221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 90433030 + ... + 90670496.

It is an arithmetic number, because the mean of its divisors is an integer number (674910652416).

Almost surely, 2^{21503055504321} is an apocalyptic number.

It is an amenable number.

21503055504321 is a deficient number, since it is larger than the sum of its proper divisors (10892655811647).

21503055504321 is a wasteful number, since it uses less digits than its factorization.

21503055504321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239624 (or 239612 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The spelling of 21503055504321 in words is "twenty-one trillion, five hundred three billion, fifty-five million, five hundred four thousand, three hundred twenty-one".