78128113 has 4 divisors (see below), whose sum is σ = 89289280. Its totient is φ = 66966948.

The previous prime is 78128081. The next prime is 78128131. The reversal of 78128113 is 31182187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78128113 - 2⁵ = 78128081 is a prime.

It is a super-2 number, since 2×78128113² = 12208004081881538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78128173) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5580573 + ... + 5580586.

It is an arithmetic number, because the mean of its divisors is an integer number (22322320).

Almost surely, 2^78128113 is an apocalyptic number.

It is an amenable number.

78128113 is a deficient number, since it is larger than the sum of its proper divisors (11161167).

78128113 is a wasteful number, since it uses less digits than its factorization.

78128113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11161166.

The product of its digits is 2688, while the sum is 31.

The square root of 78128113 is about 8839.0108609504. The cubic root of 78128113 is about 427.4996646259.

The spelling of 78128113 in words is "seventy-eight million, one hundred twenty-eight thousand, one hundred thirteen".