21533500442403 has 12 divisors (see below), whose sum is σ = 31119598831048. Its totient is φ = 14348442155040.

The previous prime is 21533500442401. The next prime is 21533500442437. The reversal of 21533500442403 is 30424400533512.

21533500442403 is a `hidden beast` number, since 21 + 5 + 3 + 350 + 0 + 44 + 240 + 3 = 666.

It is not a de Polignac number, because 21533500442403 - 2¹ = 21533500442401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21533500442401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 602048338 + ... + 602084103.

Almost surely, 2^{21533500442403} is an apocalyptic number.

21533500442403 is a deficient number, since it is larger than the sum of its proper divisors (9586098388645).

21533500442403 is a wasteful number, since it uses less digits than its factorization.

21533500442403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1204134434 (or 1204134431 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 36.

Adding to 21533500442403 its reverse (30424400533512), we get a palindrome (51957900975915).

The spelling of 21533500442403 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred million, four hundred forty-two thousand, four hundred three".