21366076242 has 64 divisors (see below), whose sum is σ = 50915589120. Its totient is φ = 5850097344.

The previous prime is 21366076241. The next prime is 21366076261. The reversal of 21366076242 is 24267066312.

It is a self number, because there is not a number n which added to its sum of digits gives 21366076242.

It is not an unprimeable number, because it can be changed into a prime (21366076241) 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 31 ways as a sum of consecutive naturals, for example, 15892 + ... + 207327.

It is an arithmetic number, because the mean of its divisors is an integer number (795556080).

Almost surely, 2^21366076242 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21366076242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25457794560).

21366076242 is an abundant number, since it is smaller than the sum of its proper divisors (29549512878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21366076242 is a wasteful number, since it uses less digits than its factorization.

21366076242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223327.

The product of its (nonzero) digits is 145152, while the sum is 39.

The spelling of 21366076242 in words is "twenty-one billion, three hundred sixty-six million, seventy-six thousand, two hundred forty-two".