78428740 has 24 divisors (see below), whose sum is σ = 177370200. Its totient is φ = 28958208.

The previous prime is 78428719. The next prime is 78428741. The reversal of 78428740 is 4782487.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11614464 + 66814276 = 3408^2 + 8174^2 .

It is a junction number, because it is equal to n+sod(n) for n = 78428693 and 78428702.

It is not an unprimeable number, because it can be changed into a prime (78428741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150565 + ... + 151084.

It is an arithmetic number, because the mean of its divisors is an integer number (7390425).

Almost surely, 2^78428740 is an apocalyptic number.

It is an amenable number.

78428740 is an abundant number, since it is smaller than the sum of its proper divisors (98941460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78428740 is a wasteful number, since it uses less digits than its factorization.

78428740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301671 (or 301669 counting only the distinct ones).

The product of its (nonzero) digits is 100352, while the sum is 40.

The square root of 78428740 is about 8856.0002258356. Note that the first 3 decimals coincide. The cubic root of 78428740 is about 428.0472842045.

The spelling of 78428740 in words is "seventy-eight million, four hundred twenty-eight thousand, seven hundred forty".