21535241523 has 4 divisors (see below), whose sum is σ = 28713655368. Its totient is φ = 14356827680.

The previous prime is 21535241491. The next prime is 21535241543. The reversal of 21535241523 is 32514253512.

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 21535241523 - 2⁵ = 21535241491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21535241543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3589206918 + ... + 3589206923.

It is an arithmetic number, because the mean of its divisors is an integer number (7178413842).

Almost surely, 2^21535241523 is an apocalyptic number.

21535241523 is a deficient number, since it is larger than the sum of its proper divisors (7178413845).

21535241523 is an equidigital number, since it uses as much as digits as its factorization.

21535241523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7178413844.

The product of its digits is 36000, while the sum is 33.

The spelling of 21535241523 in words is "twenty-one billion, five hundred thirty-five million, two hundred forty-one thousand, five hundred twenty-three".