21530534254423 has 4 divisors (see below), whose sum is σ = 21895458563880. Its totient is φ = 21165609944968.

The previous prime is 21530534254399. The next prime is 21530534254447. The reversal of 21530534254423 is 32445243503512.

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

It is an interprime number because it is at equal distance from previous prime (21530534254399) and next prime (21530534254447).

It is a cyclic number.

It is not a de Polignac number, because 21530534254423 - 2²⁵ = 21530500699991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21530534254423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530534254123) 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, 182462154640 + ... + 182462154757.

It is an arithmetic number, because the mean of its divisors is an integer number (5473864640970).

Almost surely, 2^{21530534254423} is an apocalyptic number.

21530534254423 is a deficient number, since it is larger than the sum of its proper divisors (364924309457).

21530534254423 is an equidigital number, since it uses as much as digits as its factorization.

21530534254423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364924309456.

The product of its (nonzero) digits is 1728000, while the sum is 43.

Adding to 21530534254423 its reverse (32445243503512), we get a palindrome (53975777757935).

The spelling of 21530534254423 in words is "twenty-one trillion, five hundred thirty billion, five hundred thirty-four million, two hundred fifty-four thousand, four hundred twenty-three".