21851790048 has 144 divisors (see below), whose sum is σ = 68073877872. Its totient is φ = 6594048000.

The previous prime is 21851790013. The next prime is 21851790083. The reversal of 21851790048 is 84009715812.

21851790048 is a `hidden beast` number, since 2 + 1 + 8 + 517 + 90 + 0 + 48 = 666.

It is an interprime number because it is at equal distance from previous prime (21851790013) and next prime (21851790083).

It is a tau number, because it is divible by the number of its divisors (144).

It is a junction number, because it is equal to n+sod(n) for n = 21851789985 and 21851790012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 749178 + ... + 777798.

It is an arithmetic number, because the mean of its divisors is an integer number (472735263).

Almost surely, 2^21851790048 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21851790048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34036938936).

21851790048 is an abundant number, since it is smaller than the sum of its proper divisors (46222087824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21851790048 is a wasteful number, since it uses less digits than its factorization.

21851790048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28889 (or 28878 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 21851790048 in words is "twenty-one billion, eight hundred fifty-one million, seven hundred ninety thousand, forty-eight".