2180806 has 4 divisors (see below), whose sum is σ = 3271212. Its totient is φ = 1090402.

The previous prime is 2180803. The next prime is 2180807. The reversal of 2180806 is 6080812.

2180806 is nontrivially palindromic in base 11.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2180803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545200 + ... + 545203.

It is an arithmetic number, because the mean of its divisors is an integer number (817803).

2^2180806 is an apocalyptic number.

2180806 is a deficient number, since it is larger than the sum of its proper divisors (1090406).

2180806 is a wasteful number, since it uses less digits than its factorization.

2180806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090405.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 2180806 is about 1476.7552268403. The cubic root of 2180806 is about 129.6798037045.

The spelling of 2180806 in words is "two million, one hundred eighty thousand, eight hundred six".