21042340244 has 6 divisors (see below), whose sum is σ = 36824095434. Its totient is φ = 10521170120.

The previous prime is 21042340159. The next prime is 21042340261. The reversal of 21042340244 is 44204324012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19909210000 + 1133130244 = 141100^2 + 33662^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2630292527 + ... + 2630292534.

It is an arithmetic number, because the mean of its divisors is an integer number (6137349239).

Almost surely, 2^21042340244 is an apocalyptic number.

It is an amenable number.

21042340244 is a deficient number, since it is larger than the sum of its proper divisors (15781755190).

21042340244 is a wasteful number, since it uses less digits than its factorization.

21042340244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5260585065 (or 5260585063 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21042340244 its reverse (44204324012), we get a palindrome (65246664256).

The spelling of 21042340244 in words is "twenty-one billion, forty-two million, three hundred forty thousand, two hundred forty-four".