21204240041 has 4 divisors (see below), whose sum is σ = 21563634000. Its totient is φ = 20844846084.

The previous prime is 21204240037. The next prime is 21204240059. The reversal of 21204240041 is 14004240212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21204240041 - 2² = 21204240037 is a prime.

It is a super-3 number, since 3×21204240041³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21204239995 and 21204240022.

It is not an unprimeable number, because it can be changed into a prime (21204240011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179696891 + ... + 179697008.

It is an arithmetic number, because the mean of its divisors is an integer number (5390908500).

Almost surely, 2^21204240041 is an apocalyptic number.

It is an amenable number.

21204240041 is a deficient number, since it is larger than the sum of its proper divisors (359393959).

21204240041 is an equidigital number, since it uses as much as digits as its factorization.

21204240041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359393958.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21204240041 its reverse (14004240212), we get a palindrome (35208480253).

The spelling of 21204240041 in words is "twenty-one billion, two hundred four million, two hundred forty thousand, forty-one".