128958749 has 2 divisors, whose sum is σ = 128958750. Its totient is φ = 128958748.

The previous prime is 128958707. The next prime is 128958799. The reversal of 128958749 is 947859821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125843524 + 3115225 = 11218^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 128958749 - 2¹⁶ = 128893213 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128958749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128958799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64479374 + 64479375.

It is an arithmetic number, because the mean of its divisors is an integer number (64479375).

Almost surely, 2^128958749 is an apocalyptic number.

It is an amenable number.

128958749 is a deficient number, since it is larger than the sum of its proper divisors (1).

128958749 is an equidigital number, since it uses as much as digits as its factorization.

128958749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 53.

The square root of 128958749 is about 11356.0005723846. Note that the first 3 decimals coincide. The cubic root of 128958749 is about 505.2235705824.

The spelling of 128958749 in words is "one hundred twenty-eight million, nine hundred fifty-eight thousand, seven hundred forty-nine".