78128187 has 16 divisors (see below), whose sum is σ = 106041600. Its totient is φ = 51156000.

The previous prime is 78128173. The next prime is 78128189. The reversal of 78128187 is 78182187.

It is not a de Polignac number, because 78128187 - 2¹⁰ = 78127163 is a prime.

It is a super-2 number, since 2×78128187² = 12208027207813938, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78128189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73812 + ... + 74862.

It is an arithmetic number, because the mean of its divisors is an integer number (6627600).

Almost surely, 2^78128187 is an apocalyptic number.

78128187 is a deficient number, since it is larger than the sum of its proper divisors (27913413).

78128187 is a wasteful number, since it uses less digits than its factorization.

78128187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1474.

The product of its digits is 50176, while the sum is 42.

The square root of 78128187 is about 8839.0150469382. The cubic root of 78128187 is about 427.4997995964.

The spelling of 78128187 in words is "seventy-eight million, one hundred twenty-eight thousand, one hundred eighty-seven".