2181980736 has 336 divisors, whose sum is σ = 7274253168. Its totient is φ = 619315200.

The previous prime is 2181980707. The next prime is 2181980747. The reversal of 2181980736 is 6370891812.

It can be written as a sum of positive squares in 8 ways, for example, as 144000000 + 2037980736 = 12000^2 + 45144^2 .

It is a super-2 number, since 2×2181980736² = 9522079864550203392, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2181980691 and 2181980700.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7764916 + ... + 7765196.

It is an arithmetic number, because the mean of its divisors is an integer number (21649563).

Almost surely, 2^2181980736 is an apocalyptic number.

2181980736 is a gapful number since it is divisible by the number (26) 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 2181980736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3637126584).

2181980736 is an abundant number, since it is smaller than the sum of its proper divisors (5092272432).

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

2181980736 is a wasteful number, since it uses less digits than its factorization.

2181980736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 2181980736 is about 46711.6766558427. The cubic root of 2181980736 is about 1297.0308442249.

The spelling of 2181980736 in words is "two billion, one hundred eighty-one million, nine hundred eighty thousand, seven hundred thirty-six".