2181518 has 4 divisors (see below), whose sum is σ = 3272280. Its totient is φ = 1090758.

The previous prime is 2181503. The next prime is 2181539. The reversal of 2181518 is 8151812.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545378 + ... + 545381.

It is an arithmetic number, because the mean of its divisors is an integer number (818070).

2^2181518 is an apocalyptic number.

2181518 is a deficient number, since it is larger than the sum of its proper divisors (1090762).

2181518 is a wasteful number, since it uses less digits than its factorization.

2181518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090761.

The product of its digits is 640, while the sum is 26.

The square root of 2181518 is about 1476.9962762309. The cubic root of 2181518 is about 129.6939149969.

The spelling of 2181518 in words is "two million, one hundred eighty-one thousand, five hundred eighteen".