805611471978 has 16 divisors (see below), whose sum is σ = 1663197878016. Its totient is φ = 259874668320.

The previous prime is 805611471971. The next prime is 805611472019. The reversal of 805611471978 is 879174116508.

805611471978 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 (805611471971) 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, 2165622051 + ... + 2165622422.

It is an arithmetic number, because the mean of its divisors is an integer number (103949867376).

Almost surely, 2^805611471978 is an apocalyptic number.

805611471978 is an abundant number, since it is smaller than the sum of its proper divisors (857586406038).

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

805611471978 is a wasteful number, since it uses less digits than its factorization.

805611471978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4331244509.

The product of its (nonzero) digits is 3386880, while the sum is 57.

The spelling of 805611471978 in words is "eight hundred five billion, six hundred eleven million, four hundred seventy-one thousand, nine hundred seventy-eight".