78128271 has 24 divisors (see below), whose sum is σ = 121832256. Its totient is φ = 47960640.

The previous prime is 78128261. The next prime is 78128317. The reversal of 78128271 is 17282187.

It is a happy number.

It is not a de Polignac number, because 78128271 - 2¹⁵ = 78095503 is a prime.

It is a super-2 number, since 2×78128271² = 12208053458898882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78128221) 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 23 ways as a sum of consecutive naturals, for example, 85306 + ... + 86216.

It is an arithmetic number, because the mean of its divisors is an integer number (5076344).

Almost surely, 2^78128271 is an apocalyptic number.

78128271 is a deficient number, since it is larger than the sum of its proper divisors (43703985).

78128271 is a wasteful number, since it uses less digits than its factorization.

78128271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663 (or 1660 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 78128271 is about 8839.0197985976. The cubic root of 78128271 is about 427.4999528060.

The spelling of 78128271 in words is "seventy-eight million, one hundred twenty-eight thousand, two hundred seventy-one".