671471778978 has 192 divisors, whose sum is σ = 1973515444992. Its totient is φ = 159332106240.

The previous prime is 671471778947. The next prime is 671471779051. The reversal of 671471778978 is 879877174176.

671471778978 is a `hidden beast` number, since 6 + 7 + 1 + 471 + 7 + 7 + 89 + 78 = 666.

671471778978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1555650 + ... + 1939842.

It is an arithmetic number, because the mean of its divisors is an integer number (10278726276).

Almost surely, 2^671471778978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671471778978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (986757722496).

671471778978 is an abundant number, since it is smaller than the sum of its proper divisors (1302043666014).

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

671471778978 is a wasteful number, since it uses less digits than its factorization.

671471778978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384329 (or 384326 counting only the distinct ones).

The product of its digits is 232339968, while the sum is 72.

The spelling of 671471778978 in words is "six hundred seventy-one billion, four hundred seventy-one million, seven hundred seventy-eight thousand, nine hundred seventy-eight".