2123456 has 14 divisors (see below), whose sum is σ = 4213860. Its totient is φ = 1061696.

The previous prime is 2123423. The next prime is 2123461. The reversal of 2123456 is 6543212.

2123456 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is an Ulam number.

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

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, 16526 + ... + 16653.

It is an arithmetic number, because the mean of its divisors is an integer number (300990).

2^2123456 is an apocalyptic number.

It is an amenable number.

2123456 is a deficient number, since it is larger than the sum of its proper divisors (2090404).

2123456 is an equidigital number, since it uses as much as digits as its factorization.

2123456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33191 (or 33181 counting only the distinct ones).

The product of its digits is 1440, while the sum is 23.

The square root of 2123456 is about 1457.2082898474. The cubic root of 2123456 is about 128.5329342725.

Adding to 2123456 its reverse (6543212), we get a palindrome (8666668).

The spelling of 2123456 in words is "two million, one hundred twenty-three thousand, four hundred fifty-six".