243263640 has 128 divisors (see below), whose sum is σ = 776355840. Its totient is φ = 60842496.

The previous prime is 243263633. The next prime is 243263653. The reversal of 243263640 is 46362342.

It is a happy number.

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 = 243263598 and 243263607.

It is a congruent number.

It is an unprimeable number.

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, 145449 + ... + 147111.

It is an arithmetic number, because the mean of its divisors is an integer number (6065280).

Almost surely, 2^243263640 is an apocalyptic number.

243263640 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 243263640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388177920).

243263640 is an abundant number, since it is smaller than the sum of its proper divisors (533092200).

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

243263640 is a wasteful number, since it uses less digits than its factorization.

243263640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1753 (or 1749 counting only the distinct ones).

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

The square root of 243263640 is about 15596.9112326768. The cubic root of 243263640 is about 624.2507416046.

It can be divided in two parts, 24326 and 3640, that added together give a triangular number (27966 = T₂₃₆).

The spelling of 243263640 in words is "two hundred forty-three million, two hundred sixty-three thousand, six hundred forty".