21404775239 has 4 divisors (see below), whose sum is σ = 21490053480. Its totient is φ = 21319497000.

The previous prime is 21404775229. The next prime is 21404775241. The reversal of 21404775239 is 93257740412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21404775239 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21404775239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404775229) 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, 42638744 + ... + 42639245.

It is an arithmetic number, because the mean of its divisors is an integer number (5372513370).

Almost surely, 2^21404775239 is an apocalyptic number.

21404775239 is a deficient number, since it is larger than the sum of its proper divisors (85278241).

21404775239 is an equidigital number, since it uses as much as digits as its factorization.

21404775239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85278240.

The product of its (nonzero) digits is 423360, while the sum is 44.

The spelling of 21404775239 in words is "twenty-one billion, four hundred four million, seven hundred seventy-five thousand, two hundred thirty-nine".