21200440535 has 4 divisors (see below), whose sum is σ = 25440528648. Its totient is φ = 16960352424.

The previous prime is 21200440507. The next prime is 21200440579. The reversal of 21200440535 is 53504400212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21200440535 - 2²⁰ = 21199391959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2120044049 + ... + 2120044058.

It is an arithmetic number, because the mean of its divisors is an integer number (6360132162).

Almost surely, 2^21200440535 is an apocalyptic number.

21200440535 is a deficient number, since it is larger than the sum of its proper divisors (4240088113).

21200440535 is an equidigital number, since it uses as much as digits as its factorization.

21200440535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4240088112.

The product of its (nonzero) digits is 4800, while the sum is 26.

Adding to 21200440535 its reverse (53504400212), we get a palindrome (74704840747).

The spelling of 21200440535 in words is "twenty-one billion, two hundred million, four hundred forty thousand, five hundred thirty-five".