21818238242 has 16 divisors (see below), whose sum is σ = 34176831552. Its totient is φ = 10426698480.

The previous prime is 21818238241. The next prime is 21818238259. The reversal of 21818238242 is 24283281812.

It is a self number, because there is not a number n which added to its sum of digits gives 21818238242.

It is not an unprimeable number, because it can be changed into a prime (21818238241) 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 7 ways as a sum of consecutive naturals, for example, 124313 + ... + 243084.

It is an arithmetic number, because the mean of its divisors is an integer number (2136051972).

Almost surely, 2^21818238242 is an apocalyptic number.

21818238242 is a deficient number, since it is larger than the sum of its proper divisors (12358593310).

21818238242 is a wasteful number, since it uses less digits than its factorization.

21818238242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368713.

The product of its digits is 98304, while the sum is 41.

The spelling of 21818238242 in words is "twenty-one billion, eight hundred eighteen million, two hundred thirty-eight thousand, two hundred forty-two".