21178422384 has 160 divisors (see below), whose sum is σ = 67044280320. Its totient is φ = 5622829056.

The previous prime is 21178422373. The next prime is 21178422437. The reversal of 21178422384 is 48322487112.

It is a super-2 number, since 2×21178422384² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 427782 + ... + 474714.

It is an arithmetic number, because the mean of its divisors is an integer number (419026752).

Almost surely, 2^21178422384 is an apocalyptic number.

21178422384 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 21178422384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33522140160).

21178422384 is an abundant number, since it is smaller than the sum of its proper divisors (45865857936).

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

21178422384 is a wasteful number, since it uses less digits than its factorization.

21178422384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47047 (or 47041 counting only the distinct ones).

The product of its digits is 172032, while the sum is 42.

The spelling of 21178422384 in words is "twenty-one billion, one hundred seventy-eight million, four hundred twenty-two thousand, three hundred eighty-four".