21140342442 has 72 divisors (see below), whose sum is σ = 48235385952. Its totient is φ = 6947224200.

The previous prime is 21140342441. The next prime is 21140342479. The reversal of 21140342442 is 24424304112.

21140342442 is a `hidden beast` number, since 2 + 11 + 403 + 4 + 244 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21140342441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 920317 + ... + 943007.

It is an arithmetic number, because the mean of its divisors is an integer number (669935916).

Almost surely, 2^21140342442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21140342442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24117692976).

21140342442 is an abundant number, since it is smaller than the sum of its proper divisors (27095043510).

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

21140342442 is an frugal number, since it uses more digits than its factorization.

21140342442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22788 (or 22767 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

Adding to 21140342442 its reverse (24424304112), we get a palindrome (45564646554).

It can be divided in two parts, 211 and 40342442, that added together give a triangular number (40342653 = T₈₉₈₂).

The spelling of 21140342442 in words is "twenty-one billion, one hundred forty million, three hundred forty-two thousand, four hundred forty-two".