21403351054503 has 48 divisors (see below), whose sum is σ = 34974311463936. Its totient is φ = 12498605104320.

The previous prime is 21403351054489. The next prime is 21403351054531. The reversal of 21403351054503 is 30545015330412.

21403351054503 is a `hidden beast` number, since 2 + 1 + 40 + 3 + 3 + 5 + 105 + 4 + 503 = 666.

It is not a de Polignac number, because 21403351054503 - 2¹⁷ = 21403350923431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21403351054583) 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, 27987375 + ... + 28741952.

It is an arithmetic number, because the mean of its divisors is an integer number (728631488832).

Almost surely, 2^{21403351054503} is an apocalyptic number.

21403351054503 is a deficient number, since it is larger than the sum of its proper divisors (13570960409433).

21403351054503 is a wasteful number, since it uses less digits than its factorization.

21403351054503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56729484 (or 56729481 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

Adding to 21403351054503 its reverse (30545015330412), we get a palindrome (51948366384915).

The spelling of 21403351054503 in words is "twenty-one trillion, four hundred three billion, three hundred fifty-one million, fifty-four thousand, five hundred three".