840609185978 has 8 divisors (see below), whose sum is σ = 1260938068500. Its totient is φ = 420296496480.

The previous prime is 840609185959. The next prime is 840609185981. The reversal of 840609185978 is 879581906048.

It can be written as a sum of positive squares in 2 ways, for example, as 795284053369 + 45325132609 = 891787^2 + 212897^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3917633 + ... + 4126628.

Almost surely, 2^840609185978 is an apocalyptic number.

840609185978 is a deficient number, since it is larger than the sum of its proper divisors (420328882522).

840609185978 is a wasteful number, since it uses less digits than its factorization.

840609185978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8096512.

The product of its (nonzero) digits is 34836480, while the sum is 65.

The spelling of 840609185978 in words is "eight hundred forty billion, six hundred nine million, one hundred eighty-five thousand, nine hundred seventy-eight".