21436005523 has 16 divisors (see below), whose sum is σ = 23126775840. Its totient is φ = 19802016000.

The previous prime is 21436005511. The next prime is 21436005529. The reversal of 21436005523 is 32550063412.

It is a happy number.

It is not a de Polignac number, because 21436005523 - 2⁵ = 21436005491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21436005529) 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 15 ways as a sum of consecutive naturals, for example, 1736473 + ... + 1748773.

It is an arithmetic number, because the mean of its divisors is an integer number (1445423490).

Almost surely, 2^21436005523 is an apocalyptic number.

21436005523 is a deficient number, since it is larger than the sum of its proper divisors (1690770317).

21436005523 is a wasteful number, since it uses less digits than its factorization.

21436005523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14598.

The product of its (nonzero) digits is 21600, while the sum is 31.

Adding to 21436005523 its reverse (32550063412), we get a palindrome (53986068935).

The spelling of 21436005523 in words is "twenty-one billion, four hundred thirty-six million, five thousand, five hundred twenty-three".