1778788045 has 4 divisors (see below), whose sum is σ = 2134545660. Its totient is φ = 1423030432.

The previous prime is 1778788027. The next prime is 1778788049. The reversal of 1778788045 is 5408878771.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5408878771 = 4273 ⋅1265827.

It can be written as a sum of positive squares in 2 ways, for example, as 1066218409 + 712569636 = 32653^2 + 26694^2 .

It is a cyclic number.

It is not a de Polignac number, because 1778788045 - 2⁷ = 1778787917 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1778788049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177878800 + ... + 177878809.

It is an arithmetic number, because the mean of its divisors is an integer number (533636415).

Almost surely, 2^1778788045 is an apocalyptic number.

It is an amenable number.

1778788045 is a deficient number, since it is larger than the sum of its proper divisors (355757615).

1778788045 is an equidigital number, since it uses as much as digits as its factorization.

1778788045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355757614.

The product of its (nonzero) digits is 3512320, while the sum is 55.

The square root of 1778788045 is about 42175.6807295389. The cubic root of 1778788045 is about 1211.6431572724.

The spelling of 1778788045 in words is "one billion, seven hundred seventy-eight million, seven hundred eighty-eight thousand, forty-five".