2180638920 has 32 divisors (see below), whose sum is σ = 6541917120. Its totient is φ = 581503680.

The previous prime is 2180638891. The next prime is 2180638979. The reversal of 2180638920 is 298360812.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9085876 + ... + 9086115.

It is an arithmetic number, because the mean of its divisors is an integer number (204434910).

Almost surely, 2^2180638920 is an apocalyptic number.

2180638920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2180638920 is an abundant number, since it is smaller than the sum of its proper divisors (4361278200).

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

2180638920 is a wasteful number, since it uses less digits than its factorization.

2180638920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18172005 (or 18172001 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 2180638920 is about 46697.3116999255. The cubic root of 2180638920 is about 1296.7649186246.

It can be divided in two parts, 21806 and 38920, that added together give a triangular number (60726 = T₃₄₈).

The spelling of 2180638920 in words is "two billion, one hundred eighty million, six hundred thirty-eight thousand, nine hundred twenty".