243131640 has 64 divisors (see below), whose sum is σ = 747200160. Its totient is φ = 63252480.

The previous prime is 243131639. The next prime is 243131653. The reversal of 243131640 is 46131342.

It is a super-2 number, since 2×243131640² = 118225988738179200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 243131640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19789 + ... + 29628.

Almost surely, 2^243131640 is an apocalyptic number.

243131640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243131640 is an abundant number, since it is smaller than the sum of its proper divisors (504068520).

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

243131640 is a wasteful number, since it uses less digits than its factorization.

243131640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49472 (or 49468 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 243131640 is about 15592.6790514010. The cubic root of 243131640 is about 624.1378106207.

Adding to 243131640 its reverse (46131342), we get a palindrome (289262982).

The spelling of 243131640 in words is "two hundred forty-three million, one hundred thirty-one thousand, six hundred forty".