1778780345 has 4 divisors (see below), whose sum is σ = 2134536420. Its totient is φ = 1423024272.

The previous prime is 1778780317. The next prime is 1778780357. The reversal of 1778780345 is 5430878771.

It is a happy number.

1778780345 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5430878771 = 17077 ⋅318023.

It can be written as a sum of positive squares in 2 ways, for example, as 1182053161 + 596727184 = 34381^2 + 24428^2 .

It is a cyclic number.

It is not a de Polignac number, because 1778780345 - 2⁸ = 1778780089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1778780293 and 1778780302.

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, 177878030 + ... + 177878039.

It is an arithmetic number, because the mean of its divisors is an integer number (533634105).

Almost surely, 2^1778780345 is an apocalyptic number.

It is an amenable number.

1778780345 is a deficient number, since it is larger than the sum of its proper divisors (355756075).

1778780345 is an equidigital number, since it uses as much as digits as its factorization.

1778780345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355756074.

The product of its (nonzero) digits is 1317120, while the sum is 50.

The square root of 1778780345 is about 42175.5894446065. The cubic root of 1778780345 is about 1211.6414089536.

The spelling of 1778780345 in words is "one billion, seven hundred seventy-eight million, seven hundred eighty thousand, three hundred forty-five".