21844394679 has 4 divisors (see below), whose sum is σ = 29125859576. Its totient is φ = 14562929784.

The previous prime is 21844394657. The next prime is 21844394687. The reversal of 21844394679 is 97649344812.

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

It is not a de Polignac number, because 21844394679 - 2⁸ = 21844394423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21844394609) 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, 3640732444 + ... + 3640732449.

It is an arithmetic number, because the mean of its divisors is an integer number (7281464894).

Almost surely, 2^21844394679 is an apocalyptic number.

21844394679 is a deficient number, since it is larger than the sum of its proper divisors (7281464897).

21844394679 is an equidigital number, since it uses as much as digits as its factorization.

21844394679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7281464896.

The product of its digits is 10450944, while the sum is 57.

The spelling of 21844394679 in words is "twenty-one billion, eight hundred forty-four million, three hundred ninety-four thousand, six hundred seventy-nine".