128540243 has 4 divisors (see below), whose sum is σ = 138427968. Its totient is φ = 118652520.

The previous prime is 128540239. The next prime is 128540299. The reversal of 128540243 is 342045821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128540243 - 2² = 128540239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128540233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4943843 + ... + 4943868.

It is an arithmetic number, because the mean of its divisors is an integer number (34606992).

Almost surely, 2^128540243 is an apocalyptic number.

128540243 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

128540243 is a deficient number, since it is larger than the sum of its proper divisors (9887725).

128540243 is an equidigital number, since it uses as much as digits as its factorization.

128540243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9887724.

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 128540243 is about 11337.5589524377. The cubic root of 128540243 is about 504.6764492841.

The spelling of 128540243 in words is "one hundred twenty-eight million, five hundred forty thousand, two hundred forty-three".