21044342542 has 16 divisors (see below), whose sum is σ = 32131796112. Its totient is φ = 10334257920.

The previous prime is 21044342537. The next prime is 21044342581. The reversal of 21044342542 is 24524344012.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 46048 + ... + 210259.

It is an arithmetic number, because the mean of its divisors is an integer number (2008237257).

Almost surely, 2^21044342542 is an apocalyptic number.

21044342542 is a deficient number, since it is larger than the sum of its proper divisors (11087453570).

21044342542 is a wasteful number, since it uses less digits than its factorization.

21044342542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257043.

The product of its (nonzero) digits is 30720, while the sum is 31.

Adding to 21044342542 its reverse (24524344012), we get a palindrome (45568686554).

The spelling of 21044342542 in words is "twenty-one billion, forty-four million, three hundred forty-two thousand, five hundred forty-two".