243326640 has 80 divisors (see below), whose sum is σ = 757317600. Its totient is φ = 64628736.

The previous prime is 243326599. The next prime is 243326651. The reversal of 243326640 is 46623342.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 243326598 and 243326607.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 62676 + ... + 66444.

It is an arithmetic number, because the mean of its divisors is an integer number (9466470).

Almost surely, 2^243326640 is an apocalyptic number.

243326640 is a gapful number since it is divisible by the number (20) 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 243326640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (378658800).

243326640 is an abundant number, since it is smaller than the sum of its proper divisors (513990960).

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

243326640 is a wasteful number, since it uses less digits than its factorization.

243326640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4054 (or 4048 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 30.

The square root of 243326640 is about 15598.9307325855. The cubic root of 243326640 is about 624.3046260818.

Adding to 243326640 its reverse (46623342), we get a palindrome (289949982).

The spelling of 243326640 in words is "two hundred forty-three million, three hundred twenty-six thousand, six hundred forty".