128990815 has 32 divisors (see below), whose sum is σ = 169128000. Its totient is φ = 94403584.

The previous prime is 128990809. The next prime is 128990821. The reversal of 128990815 is 518099821.

It is an interprime number because it is at equal distance from previous prime (128990809) and next prime (128990821).

It is a de Polignac number, because none of the positive numbers 2^k-128990815 is a prime.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1449291 + ... + 1449379.

It is an arithmetic number, because the mean of its divisors is an integer number (5285250).

Almost surely, 2^128990815 is an apocalyptic number.

128990815 is a deficient number, since it is larger than the sum of its proper divisors (40137185).

128990815 is an frugal number, since it uses more digits than its factorization.

128990815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 43.

The square root of 128990815 is about 11357.4123373240. The cubic root of 128990815 is about 505.2654422573.

The spelling of 128990815 in words is "one hundred twenty-eight million, nine hundred ninety thousand, eight hundred fifteen".