128897929 has 2 divisors, whose sum is σ = 128897930. Its totient is φ = 128897928.

The previous prime is 128897903. The next prime is 128897933. The reversal of 128897929 is 929798821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 113998329 + 14899600 = 10677^2 + 3860^2 .

It is a cyclic number.

It is not a de Polignac number, because 128897929 - 2¹⁵ = 128865161 is a prime.

It is a super-2 number, since 2×128897929² = 33229352200978082, which contains 22 as substring.

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 128897929.

It is not a weakly prime, because it can be changed into another prime (128897939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64448964 + 64448965.

It is an arithmetic number, because the mean of its divisors is an integer number (64448965).

Almost surely, 2^128897929 is an apocalyptic number.

It is an amenable number.

128897929 is a deficient number, since it is larger than the sum of its proper divisors (1).

128897929 is an equidigital number, since it uses as much as digits as its factorization.

128897929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 55.

The square root of 128897929 is about 11353.3223771722. The cubic root of 128897929 is about 505.1441329594.

The spelling of 128897929 in words is "one hundred twenty-eight million, eight hundred ninety-seven thousand, nine hundred twenty-nine".