21530650563573 has 4 divisors (see below), whose sum is σ = 28707534084768. Its totient is φ = 14353767042380.

The previous prime is 21530650563517. The next prime is 21530650563637. The reversal of 21530650563573 is 37536505603512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21530650563573 - 2²¹ = 21530648466421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530650563503) 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, 3588441760593 + ... + 3588441760598.

It is an arithmetic number, because the mean of its divisors is an integer number (7176883521192).

Almost surely, 2^{21530650563573} is an apocalyptic number.

It is an amenable number.

21530650563573 is a deficient number, since it is larger than the sum of its proper divisors (7176883521195).

21530650563573 is an equidigital number, since it uses as much as digits as its factorization.

21530650563573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7176883521194.

The product of its (nonzero) digits is 8505000, while the sum is 51.

The spelling of 21530650563573 in words is "twenty-one trillion, five hundred thirty billion, six hundred fifty million, five hundred sixty-three thousand, five hundred seventy-three".