128749371 has 4 divisors (see below), whose sum is σ = 171665832. Its totient is φ = 85832912.

The previous prime is 128749367. The next prime is 128749373. The reversal of 128749371 is 173947821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 173947821 = 3 ⋅57982607.

It is a cyclic number.

It is not a de Polignac number, because 128749371 - 2² = 128749367 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128749373) 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, 21458226 + ... + 21458231.

It is an arithmetic number, because the mean of its divisors is an integer number (42916458).

Almost surely, 2^128749371 is an apocalyptic number.

128749371 is a deficient number, since it is larger than the sum of its proper divisors (42916461).

128749371 is an equidigital number, since it uses as much as digits as its factorization.

128749371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42916460.

The product of its digits is 84672, while the sum is 42.

The square root of 128749371 is about 11346.7780008247. The cubic root of 128749371 is about 504.9499947219.

The spelling of 128749371 in words is "one hundred twenty-eight million, seven hundred forty-nine thousand, three hundred seventy-one".