2123818 has 4 divisors (see below), whose sum is σ = 3185730. Its totient is φ = 1061908.

The previous prime is 2123791. The next prime is 2123831. The reversal of 2123818 is 8183212.

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

It can be written as a sum of positive squares in only one way, i.e., 1423249 + 700569 = 1193^2 + 837^2 .

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 2123792 and 2123801.

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 as a sum of consecutive naturals, namely, 530953 + ... + 530956.

2^2123818 is an apocalyptic number.

2123818 is a deficient number, since it is larger than the sum of its proper divisors (1061912).

2123818 is a wasteful number, since it uses less digits than its factorization.

2123818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061911.

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

The square root of 2123818 is about 1457.3324946628. The cubic root of 2123818 is about 128.5402378190.

The spelling of 2123818 in words is "two million, one hundred twenty-three thousand, eight hundred eighteen".