21342042505 has 64 divisors (see below), whose sum is σ = 32873195520. Its totient is φ = 12948249600.

The previous prime is 21342042503. The next prime is 21342042571. The reversal of 21342042505 is 50524024312.

It is not a de Polignac number, because 21342042505 - 2¹ = 21342042503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21342042503) 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 63 ways as a sum of consecutive naturals, for example, 1473750 + ... + 1488160.

It is an arithmetic number, because the mean of its divisors is an integer number (513643680).

Almost surely, 2^21342042505 is an apocalyptic number.

It is an amenable number.

21342042505 is a deficient number, since it is larger than the sum of its proper divisors (11531153015).

21342042505 is a wasteful number, since it uses less digits than its factorization.

21342042505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14590.

The product of its (nonzero) digits is 9600, while the sum is 28.

Adding to 21342042505 its reverse (50524024312), we get a palindrome (71866066817).

The spelling of 21342042505 in words is "twenty-one billion, three hundred forty-two million, forty-two thousand, five hundred five".