21033242042 has 4 divisors (see below), whose sum is σ = 31549863066. Its totient is φ = 10516621020.

The previous prime is 21033242039. The next prime is 21033242047. The reversal of 21033242042 is 24024233012.

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., 13119182521 + 7914059521 = 114539^2 + 88961^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21033241999 and 21033242017.

It is not an unprimeable number, because it can be changed into a prime (21033242047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5258310509 + ... + 5258310512.

Almost surely, 2^21033242042 is an apocalyptic number.

21033242042 is a deficient number, since it is larger than the sum of its proper divisors (10516621024).

21033242042 is a wasteful number, since it uses less digits than its factorization.

21033242042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10516621023.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21033242042 its reverse (24024233012), we get a palindrome (45057475054).

The spelling of 21033242042 in words is "twenty-one billion, thirty-three million, two hundred forty-two thousand, forty-two".