128996217 has 12 divisors (see below), whose sum is σ = 212946240. Its totient is φ = 73712088.

The previous prime is 128996207. The next prime is 128996227. The reversal of 128996217 is 712699821.

128996217 is a `hidden beast` number, since 12 + 8 + 9 + 9 + 621 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (128996207) and next prime (128996227).

It is not a de Polignac number, because 128996217 - 2⁴ = 128996201 is a prime.

It is a super-2 number, since 2×128996217² = 33280048000622178, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (128996207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1023717 + ... + 1023842.

It is an arithmetic number, because the mean of its divisors is an integer number (17745520).

Almost surely, 2^128996217 is an apocalyptic number.

It is an amenable number.

128996217 is a deficient number, since it is larger than the sum of its proper divisors (83950023).

128996217 is a wasteful number, since it uses less digits than its factorization.

128996217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2047572 (or 2047569 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 128996217 is about 11357.6501530906. The cubic root of 128996217 is about 505.2724954877.

The spelling of 128996217 in words is "one hundred twenty-eight million, nine hundred ninety-six thousand, two hundred seventeen".