99128257 has 2 divisors, whose sum is σ = 99128258. Its totient is φ = 99128256.

The previous prime is 99128251. The next prime is 99128299. The reversal of 99128257 is 75282199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83832336 + 15295921 = 9156^2 + 3911^2 .

It is a cyclic number.

It is not a de Polignac number, because 99128257 - 2⁷ = 99128129 is a prime.

It is a super-2 number, since 2×99128257² = 19652822671716098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (99128251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49564128 + 49564129.

It is an arithmetic number, because the mean of its divisors is an integer number (49564129).

Almost surely, 2^99128257 is an apocalyptic number.

It is an amenable number.

99128257 is a deficient number, since it is larger than the sum of its proper divisors (1).

99128257 is an equidigital number, since it uses as much as digits as its factorization.

99128257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 99128257 is about 9956.3174417050. The cubic root of 99128257 is about 462.8061875114.

The spelling of 99128257 in words is "ninety-nine million, one hundred twenty-eight thousand, two hundred fifty-seven".