21335120242 has 4 divisors (see below), whose sum is σ = 32002680366. Its totient is φ = 10667560120.

The previous prime is 21335120179. The next prime is 21335120293. The reversal of 21335120242 is 24202153312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11807212921 + 9527907321 = 108661^2 + 97611^2 .

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 as a sum of consecutive naturals, namely, 5333780059 + ... + 5333780062.

Almost surely, 2^21335120242 is an apocalyptic number.

21335120242 is a deficient number, since it is larger than the sum of its proper divisors (10667560124).

21335120242 is a wasteful number, since it uses less digits than its factorization.

21335120242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10667560123.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21335120242 its reverse (24202153312), we get a palindrome (45537273554).

The spelling of 21335120242 in words is "twenty-one billion, three hundred thirty-five million, one hundred twenty thousand, two hundred forty-two".