243746640 has 240 divisors, whose sum is σ = 877443840. Its totient is φ = 60487680.

The previous prime is 243746623. The next prime is 243746669. The reversal of 243746640 is 46647342.

243746640 is a `hidden beast` number, since 2 + 4 + 3 + 7 + 4 + 6 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×243746640² = 118824849022579200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 243746595 and 243746604.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 678781 + ... + 679139.

It is an arithmetic number, because the mean of its divisors is an integer number (3656016).

Almost surely, 2^243746640 is an apocalyptic number.

243746640 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 243746640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (438721920).

243746640 is an abundant number, since it is smaller than the sum of its proper divisors (633697200).

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

243746640 is a wasteful number, since it uses less digits than its factorization.

243746640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 36.

The square root of 243746640 is about 15612.3873895058. The cubic root of 243746640 is about 624.6636184551.

The spelling of 243746640 in words is "two hundred forty-three million, seven hundred forty-six thousand, six hundred forty".