21203002554503 has 12 divisors (see below), whose sum is σ = 26906964281352. Its totient is φ = 16521820171920.

The previous prime is 21203002554493. The next prime is 21203002554523. The reversal of 21203002554503 is 30545520030212.

It is not a de Polignac number, because 21203002554503 - 2⁶ = 21203002554439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21203002554503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203002554523) 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, 19668833000 + ... + 19668834077.

It is an arithmetic number, because the mean of its divisors is an integer number (2242247023446).

Almost surely, 2^{21203002554503} is an apocalyptic number.

21203002554503 is a deficient number, since it is larger than the sum of its proper divisors (5703961726849).

21203002554503 is a wasteful number, since it uses less digits than its factorization.

21203002554503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39337667102 (or 39337667095 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 32.

Adding to 21203002554503 its reverse (30545520030212), we get a palindrome (51748522584715).

The spelling of 21203002554503 in words is "twenty-one trillion, two hundred three billion, two million, five hundred fifty-four thousand, five hundred three".