2181845540 has 36 divisors (see below), whose sum is σ = 5329939356. Its totient is φ = 748060992.

The previous prime is 2181845473. The next prime is 2181845543. The reversal of 2181845540 is 455481812.

It can be written as a sum of positive squares in 2 ways, for example, as 1437319744 + 744525796 = 37912^2 + 27286^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2181845494 and 2181845503.

It is not an unprimeable number, because it can be changed into a prime (2181845543) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1112207 + ... + 1114166.

It is an arithmetic number, because the mean of its divisors is an integer number (148053871).

Almost surely, 2^2181845540 is an apocalyptic number.

2181845540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2181845540 is an abundant number, since it is smaller than the sum of its proper divisors (3148093816).

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

2181845540 is a wasteful number, since it uses less digits than its factorization.

2181845540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2226396 (or 2226387 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 38.

The square root of 2181845540 is about 46710.2295006137. The cubic root of 2181845540 is about 1297.0040555674.

The spelling of 2181845540 in words is "two billion, one hundred eighty-one million, eight hundred forty-five thousand, five hundred forty".