21240412559 has 4 divisors (see below), whose sum is σ = 21308273616. Its totient is φ = 21172551504.

The previous prime is 21240412517. The next prime is 21240412573. The reversal of 21240412559 is 95521404212.

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 21240412559 - 2²⁴ = 21223635343 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 (21240412859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33930059 + ... + 33930684.

It is an arithmetic number, because the mean of its divisors is an integer number (5327068404).

Almost surely, 2^21240412559 is an apocalyptic number.

21240412559 is a deficient number, since it is larger than the sum of its proper divisors (67861057).

21240412559 is an equidigital number, since it uses as much as digits as its factorization.

21240412559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67861056.

The product of its (nonzero) digits is 28800, while the sum is 35.

The spelling of 21240412559 in words is "twenty-one billion, two hundred forty million, four hundred twelve thousand, five hundred fifty-nine".