378195561 has 20 divisors (see below), whose sum is σ = 567453700. Its totient is φ = 251017056.

The previous prime is 378195557. The next prime is 378195563. The reversal of 378195561 is 165591873.

It is a happy number.

378195561 is a `hidden beast` number, since 3 + 7 + 81 + 9 + 5 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 357210000 + 20985561 = 18900^2 + 4581^2 .

It is not a de Polignac number, because 378195561 - 2² = 378195557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (378195563) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8355 + ... + 28743.

It is an arithmetic number, because the mean of its divisors is an integer number (28372685).

Almost surely, 2^378195561 is an apocalyptic number.

It is an amenable number.

378195561 is a deficient number, since it is larger than the sum of its proper divisors (189258139).

378195561 is a wasteful number, since it uses less digits than its factorization.

378195561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20630 (or 20621 counting only the distinct ones).

The product of its digits is 226800, while the sum is 45.

The square root of 378195561 is about 19447.2507311445. The cubic root of 378195561 is about 723.1673481872.

The spelling of 378195561 in words is "three hundred seventy-eight million, one hundred ninety-five thousand, five hundred sixty-one".