2181768 has 16 divisors (see below), whose sum is σ = 5454480. Its totient is φ = 727248.

The previous prime is 2181737. The next prime is 2181833. The reversal of 2181768 is 8671812.

It is a happy number.

It is a super-2 number, since 2×2181768² = 9520223211648, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45430 + ... + 45477.

It is an arithmetic number, because the mean of its divisors is an integer number (340905).

2^2181768 is an apocalyptic number.

It is an amenable number.

2181768 is an abundant number, since it is smaller than the sum of its proper divisors (3272712).

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

2181768 is a wasteful number, since it uses less digits than its factorization.

2181768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90916 (or 90912 counting only the distinct ones).

The product of its digits is 5376, while the sum is 33.

The square root of 2181768 is about 1477.0809050286. The cubic root of 2181768 is about 129.6988690764.

The spelling of 2181768 in words is "two million, one hundred eighty-one thousand, seven hundred sixty-eight".