128918247 has 4 divisors (see below), whose sum is σ = 171891000. Its totient is φ = 85945496.

The previous prime is 128918221. The next prime is 128918261. The reversal of 128918247 is 742819821.

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 128918247 - 2¹⁴ = 128901863 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128918199 and 128918208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128918267) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 21486372 + ... + 21486377.

It is an arithmetic number, because the mean of its divisors is an integer number (42972750).

Almost surely, 2^128918247 is an apocalyptic number.

128918247 is a deficient number, since it is larger than the sum of its proper divisors (42972753).

128918247 is an equidigital number, since it uses as much as digits as its factorization.

128918247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42972752.

The product of its digits is 64512, while the sum is 42.

The square root of 128918247 is about 11354.2171460652. The cubic root of 128918247 is about 505.1706732857.

The spelling of 128918247 in words is "one hundred twenty-eight million, nine hundred eighteen thousand, two hundred forty-seven".