78128774 has 4 divisors (see below), whose sum is σ = 117193164. Its totient is φ = 39064386.

The previous prime is 78128717. The next prime is 78128789. The reversal of 78128774 is 47782187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47782187 = 83 ⋅575689.

It is a super-2 number, since 2×78128774² = 12208210653486152, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19532192 + ... + 19532195.

It is an arithmetic number, because the mean of its divisors is an integer number (29298291).

Almost surely, 2^78128774 is an apocalyptic number.

78128774 is a deficient number, since it is larger than the sum of its proper divisors (39064390).

78128774 is a wasteful number, since it uses less digits than its factorization.

78128774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39064389.

The product of its digits is 175616, while the sum is 44.

The square root of 78128774 is about 8839.0482519330. The cubic root of 78128774 is about 427.5008702375.

The spelling of 78128774 in words is "seventy-eight million, one hundred twenty-eight thousand, seven hundred seventy-four".