21200443042 has 4 divisors (see below), whose sum is σ = 31800664566. Its totient is φ = 10600221520.

The previous prime is 21200443031. The next prime is 21200443063. The reversal of 21200443042 is 24034400212.

It is a happy number.

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., 21004415041 + 196028001 = 144929^2 + 14001^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5300110759 + ... + 5300110762.

Almost surely, 2^21200443042 is an apocalyptic number.

21200443042 is a deficient number, since it is larger than the sum of its proper divisors (10600221524).

21200443042 is a wasteful number, since it uses less digits than its factorization.

21200443042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10600221523.

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21200443042 its reverse (24034400212), we get a palindrome (45234843254).

The spelling of 21200443042 in words is "twenty-one billion, two hundred million, four hundred forty-three thousand, forty-two".