21115502501603 has 4 divisors (see below), whose sum is σ = 21140083995480. Its totient is φ = 21090921007728.

The previous prime is 21115502501567. The next prime is 21115502501623. The reversal of 21115502501603 is 30610520551112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21115502501603 - 2⁶ = 21115502501539 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 21115502501603.

It is not an unprimeable number, because it can be changed into a prime (21115502501623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12290745650 + ... + 12290747367.

It is an arithmetic number, because the mean of its divisors is an integer number (5285020998870).

Almost surely, 2^{21115502501603} is an apocalyptic number.

21115502501603 is a deficient number, since it is larger than the sum of its proper divisors (24581493877).

21115502501603 is an equidigital number, since it uses as much as digits as its factorization.

21115502501603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24581493876.

The product of its (nonzero) digits is 9000, while the sum is 32.

The spelling of 21115502501603 in words is "twenty-one trillion, one hundred fifteen billion, five hundred two million, five hundred one thousand, six hundred three".