21115526245523 has 4 divisors (see below), whose sum is σ = 22033592604048. Its totient is φ = 20197459887000.

The previous prime is 21115526245511. The next prime is 21115526245543. The reversal of 21115526245523 is 32554262551112.

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 21115526245523 - 2⁴² = 16717479734419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21115526245543) 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, 459033179228 + ... + 459033179273.

It is an arithmetic number, because the mean of its divisors is an integer number (5508398151012).

Almost surely, 2^{21115526245523} is an apocalyptic number.

21115526245523 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21115526245523 is a deficient number, since it is larger than the sum of its proper divisors (918066358525).

21115526245523 is an equidigital number, since it uses as much as digits as its factorization.

21115526245523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918066358524.

The product of its digits is 720000, while the sum is 44.

Adding to 21115526245523 its reverse (32554262551112), we get a palindrome (53669788796635).

The spelling of 21115526245523 in words is "twenty-one trillion, one hundred fifteen billion, five hundred twenty-six million, two hundred forty-five thousand, five hundred twenty-three".