21728333944 has 8 divisors (see below), whose sum is σ = 40740626160. Its totient is φ = 10864166968.

The previous prime is 21728333929. The next prime is 21728333959. The reversal of 21728333944 is 44933382712.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21728333929) and next prime (21728333959).

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21728333894 and 21728333903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1358020864 + ... + 1358020879.

It is an arithmetic number, because the mean of its divisors is an integer number (5092578270).

Almost surely, 2^21728333944 is an apocalyptic number.

It is an amenable number.

21728333944 is a deficient number, since it is larger than the sum of its proper divisors (19012292216).

21728333944 is a wasteful number, since it uses less digits than its factorization.

21728333944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2716041749 (or 2716041745 counting only the distinct ones).

The product of its digits is 870912, while the sum is 46.

The spelling of 21728333944 in words is "twenty-one billion, seven hundred twenty-eight million, three hundred thirty-three thousand, nine hundred forty-four".