18165648400 has 135 divisors (see below), whose sum is σ = 45779232919. Its totient is φ = 6926613760.

The previous prime is 18165648373. The next prime is 18165648407. The reversal of 18165648400 is 484656181.

The square root of 18165648400 is 134780.

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

It can be written as a sum of positive squares in 4 ways, for example, as 2876820496 + 15288827904 = 53636^2 + 123648^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18165648407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 61998654 + ... + 61998946.

Almost surely, 2^18165648400 is an apocalyptic number.

18165648400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18165648400 is the 134780-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18165648400

18165648400 is an abundant number, since it is smaller than the sum of its proper divisors (27613584519).

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

18165648400 is an equidigital number, since it uses as much as digits as its factorization.

18165648400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 650 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 18165648400 in words is "eighteen billion, one hundred sixty-five million, six hundred forty-eight thousand, four hundred".