21420441244 has 24 divisors (see below), whose sum is σ = 37728029808. Its totient is φ = 10641227520.

The previous prime is 21420441223. The next prime is 21420441313. The reversal of 21420441244 is 44214402412.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 360324 + ... + 415540.

It is an arithmetic number, because the mean of its divisors is an integer number (1572001242).

Almost surely, 2^21420441244 is an apocalyptic number.

It is an amenable number.

21420441244 is a deficient number, since it is larger than the sum of its proper divisors (16307588564).

21420441244 is a wasteful number, since it uses less digits than its factorization.

21420441244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55845 (or 55843 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 21420441244 its reverse (44214402412), we get a palindrome (65634843656).

The spelling of 21420441244 in words is "twenty-one billion, four hundred twenty million, four hundred forty-one thousand, two hundred forty-four".