243806640 has 320 divisors, whose sum is σ = 959938560. Its totient is φ = 49720320.

The previous prime is 243806621. The next prime is 243806657. The reversal of 243806640 is 46608342.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1459837 + ... + 1460003.

It is an arithmetic number, because the mean of its divisors is an integer number (2999808).

Almost surely, 2^243806640 is an apocalyptic number.

243806640 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 243806640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (479969280).

243806640 is an abundant number, since it is smaller than the sum of its proper divisors (716131920).

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

243806640 is a wasteful number, since it uses less digits than its factorization.

243806640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 243806640 is about 15614.3088223591. The cubic root of 243806640 is about 624.7148694073.

The spelling of 243806640 in words is "two hundred forty-three million, eight hundred six thousand, six hundred forty".