21646470384 has 480 divisors, whose sum is σ = 78358984704. Its totient is φ = 5415621120.

The previous prime is 21646470383. The next prime is 21646470449. The reversal of 21646470384 is 48307464612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21646470383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 39572799 + ... + 39573345.

Almost surely, 2^21646470384 is an apocalyptic number.

21646470384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21646470384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39179492352).

21646470384 is an abundant number, since it is smaller than the sum of its proper divisors (56712514320).

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

21646470384 is a wasteful number, since it uses less digits than its factorization.

21646470384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705 (or 696 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The spelling of 21646470384 in words is "twenty-one billion, six hundred forty-six million, four hundred seventy thousand, three hundred eighty-four".