21365555235603 has 16 divisors (see below), whose sum is σ = 30954058521600. Its totient is φ = 13058743436640.

The previous prime is 21365555235601. The next prime is 21365555235659. The reversal of 21365555235603 is 30653255556312.

It is not a de Polignac number, because 21365555235603 - 2¹ = 21365555235601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21365555235601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6045712788 + ... + 6045716321.

It is an arithmetic number, because the mean of its divisors is an integer number (1934628657600).

Almost surely, 2^{21365555235603} is an apocalyptic number.

21365555235603 is a deficient number, since it is larger than the sum of its proper divisors (9588503285997).

21365555235603 is a wasteful number, since it uses less digits than its factorization.

21365555235603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12091429162.

The product of its (nonzero) digits is 12150000, while the sum is 51.

The spelling of 21365555235603 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred fifty-five million, two hundred thirty-five thousand, six hundred three".