7899447078 has 40 divisors (see below), whose sum is σ = 17949943440. Its totient is φ = 2596058640.

The previous prime is 7899447077. The next prime is 7899447091. The reversal of 7899447078 is 8707449987.

It is a happy number.

7899447078 is a `hidden beast` number, since 7 + 8 + 9 + 94 + 470 + 78 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7899447071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 331893 + ... + 354896.

It is an arithmetic number, because the mean of its divisors is an integer number (448748586).

Almost surely, 2^7899447078 is an apocalyptic number.

7899447078 is an abundant number, since it is smaller than the sum of its proper divisors (10050496362).

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

7899447078 is a wasteful number, since it uses less digits than its factorization.

7899447078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686874 (or 686865 counting only the distinct ones).

The product of its (nonzero) digits is 28449792, while the sum is 63.

The square root of 7899447078 is about 88878.8336894674. The cubic root of 7899447078 is about 1991.5852353542.

The spelling of 7899447078 in words is "seven billion, eight hundred ninety-nine million, four hundred forty-seven thousand, seventy-eight".