2181780900 has 288 divisors, whose sum is σ = 7684924800. Its totient is φ = 527731200.

The previous prime is 2181780889. The next prime is 2181780919. The reversal of 2181780900 is 90871812.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2140591 + ... + 2141609.

Almost surely, 2^2181780900 is an apocalyptic number.

2181780900 is a gapful number since it is divisible by the number (20) 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 2181780900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3842462400).

2181780900 is an abundant number, since it is smaller than the sum of its proper divisors (5503143900).

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

2181780900 is a wasteful number, since it uses less digits than its factorization.

2181780900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116 (or 1103 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 2181780900 is about 46709.5375699653. The cubic root of 2181780900 is about 1296.9912469659.

The spelling of 2181780900 in words is "two billion, one hundred eighty-one million, seven hundred eighty thousand, nine hundred".