243215640 has 96 divisors (see below), whose sum is σ = 799437600. Its totient is φ = 64120320.

The previous prime is 243215629. The next prime is 243215653. The reversal of 243215640 is 46512342.

243215640 is a `hidden beast` number, since 2 + 4 + 3 + 2 + 15 + 640 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28245 + ... + 35835.

It is an arithmetic number, because the mean of its divisors is an integer number (8327475).

Almost surely, 2^243215640 is an apocalyptic number.

243215640 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 243215640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399718800).

243215640 is an abundant number, since it is smaller than the sum of its proper divisors (556221960).

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

243215640 is a wasteful number, since it uses less digits than its factorization.

243215640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7697 (or 7690 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 243215640 is about 15595.3723905523. The cubic root of 243215640 is about 624.2096805201.

Adding to 243215640 its reverse (46512342), we get a palindrome (289727982).

The spelling of 243215640 in words is "two hundred forty-three million, two hundred fifteen thousand, six hundred forty".