243591640 has 32 divisors (see below), whose sum is σ = 580322880. Its totient is φ = 91704832.

The previous prime is 243591631. The next prime is 243591653. The reversal of 243591640 is 46195342.

It is a happy number.

243591640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 243591596 and 243591605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178432 + ... + 179791.

It is an arithmetic number, because the mean of its divisors is an integer number (18135090).

Almost surely, 2^243591640 is an apocalyptic number.

243591640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243591640 is an abundant number, since it is smaller than the sum of its proper divisors (336731240).

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

243591640 is a wasteful number, since it uses less digits than its factorization.

243591640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358251 (or 358247 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 243591640 is about 15607.4225931125. The cubic root of 243591640 is about 624.5311812223.

The spelling of 243591640 in words is "two hundred forty-three million, five hundred ninety-one thousand, six hundred forty".