21327616573 has 4 divisors (see below), whose sum is σ = 21329724060. Its totient is φ = 21325509088.

The previous prime is 21327616567. The next prime is 21327616631. The reversal of 21327616573 is 37561672312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16990340409 + 4337276164 = 130347^2 + 65858^2 .

It is a cyclic number.

It is not a de Polignac number, because 21327616573 - 2⁹ = 21327616061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21327616873) 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, 1038490 + ... + 1058827.

It is an arithmetic number, because the mean of its divisors is an integer number (5332431015).

Almost surely, 2^21327616573 is an apocalyptic number.

It is an amenable number.

21327616573 is a deficient number, since it is larger than the sum of its proper divisors (2107487).

21327616573 is a wasteful number, since it uses less digits than its factorization.

21327616573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2107486.

The product of its digits is 317520, while the sum is 43.

The spelling of 21327616573 in words is "twenty-one billion, three hundred twenty-seven million, six hundred sixteen thousand, five hundred seventy-three".