1816123840 has 224 divisors, whose sum is σ = 4740249600. Its totient is φ = 661032960.

The previous prime is 1816123801. The next prime is 1816123843. The reversal of 1816123840 is 483216181.

It is a junction number, because it is equal to n+sod(n) for n = 1816123796 and 1816123805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1816123843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16973067 + ... + 16973173.

Almost surely, 2^1816123840 is an apocalyptic number.

1816123840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1816123840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2370124800).

1816123840 is an abundant number, since it is smaller than the sum of its proper divisors (2924125760).

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

1816123840 is a wasteful number, since it uses less digits than its factorization.

1816123840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 1816123840 is about 42616.0045053499. The cubic root of 1816123840 is about 1220.0617723806.

The spelling of 1816123840 in words is "one billion, eight hundred sixteen million, one hundred twenty-three thousand, eight hundred forty".