78440004 has 18 divisors (see below), whose sum is σ = 198278990. Its totient is φ = 26146656.

The previous prime is 78440003. The next prime is 78440017. The reversal of 78440004 is 40004487.

It can be written as a sum of positive squares in only one way, i.e., 40985604 + 37454400 = 6402^2 + 6120^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 78440004.

It is not an unprimeable number, because it can be changed into a prime (78440003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1089409 + ... + 1089480.

Almost surely, 2^78440004 is an apocalyptic number.

It is an amenable number.

78440004 is an abundant number, since it is smaller than the sum of its proper divisors (119838986).

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

78440004 is a wasteful number, since it uses less digits than its factorization.

78440004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2178899 (or 2178894 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 27.

The square root of 78440004 is about 8856.6361560132. The cubic root of 78440004 is about 428.0677753909.

The spelling of 78440004 in words is "seventy-eight million, four hundred forty thousand, four".