2178638028 has 72 divisors (see below), whose sum is σ = 6313099520. Its totient is φ = 620563680.

The previous prime is 2178637961. The next prime is 2178638029. The reversal of 2178638028 is 8208368712.

2178638028 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 638 + 0 + 2 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (2178638029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70353 + ... + 96471.

Almost surely, 2^2178638028 is an apocalyptic number.

2178638028 is a gapful number since it is divisible by the number (28) 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 2178638028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3156549760).

2178638028 is an abundant number, since it is smaller than the sum of its proper divisors (4134461492).

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

2178638028 is a wasteful number, since it uses less digits than its factorization.

2178638028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26467 (or 26462 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 2178638028 is about 46675.8827233080. The cubic root of 2178638028 is about 1296.3681724331.

The spelling of 2178638028 in words is "two billion, one hundred seventy-eight million, six hundred thirty-eight thousand, twenty-eight".