813640978 has 16 divisors (see below), whose sum is σ = 1293304320. Its totient is φ = 382578496.

The previous prime is 813640943. The next prime is 813640979. The reversal of 813640978 is 879046318.

It is a happy number.

813640978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (813640979) 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, 35775 + ... + 53917.

It is an arithmetic number, because the mean of its divisors is an integer number (80831520).

Almost surely, 2^813640978 is an apocalyptic number.

813640978 is a deficient number, since it is larger than the sum of its proper divisors (479663342).

813640978 is a wasteful number, since it uses less digits than its factorization.

813640978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19481.

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 813640978 is about 28524.3926841572. The cubic root of 813640978 is about 933.5643759933.

The spelling of 813640978 in words is "eight hundred thirteen million, six hundred forty thousand, nine hundred seventy-eight".