2181530 has 32 divisors (see below), whose sum is σ = 4297104. Its totient is φ = 792576.

The previous prime is 2181503. The next prime is 2181539. The reversal of 2181530 is 351812.

It is a Cunningham number, because it is equal to 1477²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 978121 + 1203409 = 989^2 + 1097^2 .

It is not an unprimeable number, because it can be changed into a prime (2181539) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12524 + ... + 12696.

2^2181530 is an apocalyptic number.

2181530 is a deficient number, since it is larger than the sum of its proper divisors (2115574).

2181530 is a wasteful number, since it uses less digits than its factorization.

2181530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 2181530 is about 1477.0003385240. Note that the first 3 decimals coincide. The cubic root of 2181530 is about 129.6941528014.

The spelling of 2181530 in words is "two million, one hundred eighty-one thousand, five hundred thirty".