128422749 has 16 divisors (see below), whose sum is σ = 210745472. Its totient is φ = 67739328.

The previous prime is 128422733. The next prime is 128422757. The reversal of 128422749 is 947224821.

It is a happy number.

It is not a de Polignac number, because 128422749 - 2⁴ = 128422733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128422799) 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 15 ways as a sum of consecutive naturals, for example, 234934 + ... + 235479.

It is an arithmetic number, because the mean of its divisors is an integer number (13171592).

Almost surely, 2^128422749 is an apocalyptic number.

It is an amenable number.

128422749 is a deficient number, since it is larger than the sum of its proper divisors (82322723).

128422749 is a wasteful number, since it uses less digits than its factorization.

128422749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 470436.

The product of its digits is 64512, while the sum is 39.

The square root of 128422749 is about 11332.3761409512. The cubic root of 128422749 is about 504.5226335621.

The spelling of 128422749 in words is "one hundred twenty-eight million, four hundred twenty-two thousand, seven hundred forty-nine".