1816123456 has 63 divisors (see below), whose sum is σ = 4197773037. Its totient is φ = 777315840.

The previous prime is 1816123423. The next prime is 1816123459. The reversal of 1816123456 is 6543216181.

It is a happy number.

The square root of 1816123456 is 42616.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4769856 + 1811353600 = 2184^2 + 42560^2 .

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1816123459) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2386116 + ... + 2386876.

Almost surely, 2^1816123456 is an apocalyptic number.

1816123456 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1816123456 is the 42616-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1816123456

1816123456 is an abundant number, since it is smaller than the sum of its proper divisors (2381649581).

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

1816123456 is an frugal number, since it uses more digits than its factorization.

1816123456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1548 (or 770 counting only the distinct ones).

The product of its digits is 34560, while the sum is 37.

The cubic root of 1816123456 is about 1220.0616863909.

The spelling of 1816123456 in words is "one billion, eight hundred sixteen million, one hundred twenty-three thousand, four hundred fifty-six".