21603272021563 has 4 divisors (see below), whose sum is σ = 22187144238400. Its totient is φ = 21019399804728.

The previous prime is 21603272021477. The next prime is 21603272021633. The reversal of 21603272021563 is 36512027230612.

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 21603272021563 - 2¹⁷ = 21603271890491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21603272021063) 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, 291936108363 + ... + 291936108436.

It is an arithmetic number, because the mean of its divisors is an integer number (5546786059600).

Almost surely, 2^{21603272021563} is an apocalyptic number.

21603272021563 is a deficient number, since it is larger than the sum of its proper divisors (583872216837).

21603272021563 is an equidigital number, since it uses as much as digits as its factorization.

21603272021563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583872216836.

The product of its (nonzero) digits is 181440, while the sum is 40.

The spelling of 21603272021563 in words is "twenty-one trillion, six hundred three billion, two hundred seventy-two million, twenty-one thousand, five hundred sixty-three".