21404431444 has 12 divisors (see below), whose sum is σ = 40863005568. Its totient is φ = 9729287000.

The previous prime is 21404431429. The next prime is 21404431453. The reversal of 21404431444 is 44413440412.

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, 243232132 + ... + 243232219.

It is an arithmetic number, because the mean of its divisors is an integer number (3405250464).

Almost surely, 2^21404431444 is an apocalyptic number.

It is an amenable number.

21404431444 is a deficient number, since it is larger than the sum of its proper divisors (19458574124).

21404431444 is a wasteful number, since it uses less digits than its factorization.

21404431444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486464366 (or 486464364 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 31.

Adding to 21404431444 its reverse (44413440412), we get a palindrome (65817871856).

The spelling of 21404431444 in words is "twenty-one billion, four hundred four million, four hundred thirty-one thousand, four hundred forty-four".