21648800178 has 160 divisors (see below), whose sum is σ = 52286217984. Its totient is φ = 6670937088.

The previous prime is 21648800177. The next prime is 21648800191. The reversal of 21648800178 is 87100884612.

It is not an unprimeable number, because it can be changed into a prime (21648800177) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 47371326 + ... + 47371782.

Almost surely, 2^21648800178 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21648800178, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26143108992).

21648800178 is an abundant number, since it is smaller than the sum of its proper divisors (30637417806).

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

21648800178 is a wasteful number, since it uses less digits than its factorization.

21648800178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 45.

The spelling of 21648800178 in words is "twenty-one billion, six hundred forty-eight million, eight hundred thousand, one hundred seventy-eight".