21530711723263 has 4 divisors (see below), whose sum is σ = 21530745956448. Its totient is φ = 21530677490080.

The previous prime is 21530711723251. The next prime is 21530711723281. The reversal of 21530711723263 is 36232711703512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21530711723263 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 (21530711723863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16155178 + ... + 17437063.

It is an arithmetic number, because the mean of its divisors is an integer number (5382686489112).

Almost surely, 2^{21530711723263} is an apocalyptic number.

21530711723263 is a deficient number, since it is larger than the sum of its proper divisors (34233185).

21530711723263 is an equidigital number, since it uses as much as digits as its factorization.

21530711723263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34233184.

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

The spelling of 21530711723263 in words is "twenty-one trillion, five hundred thirty billion, seven hundred eleven million, seven hundred twenty-three thousand, two hundred sixty-three".