2181788680 has 32 divisors (see below), whose sum is σ = 5067383040. Its totient is φ = 844562880.

The previous prime is 2181788669. The next prime is 2181788683. The reversal of 2181788680 is 868871812.

It is a super-2 number, since 2×2181788680² = 9520403688352284800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (2181788683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 878514 + ... + 880993.

It is an arithmetic number, because the mean of its divisors is an integer number (158355720).

Almost surely, 2^2181788680 is an apocalyptic number.

2181788680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2181788680 is an abundant number, since it is smaller than the sum of its proper divisors (2885594360).

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

2181788680 is a wasteful number, since it uses less digits than its factorization.

2181788680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1759549 (or 1759545 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 49.

The square root of 2181788680 is about 46709.6208505271. The cubic root of 2181788680 is about 1296.9927886086.

The spelling of 2181788680 in words is "two billion, one hundred eighty-one million, seven hundred eighty-eight thousand, six hundred eighty".