778556045 has 4 divisors (see below), whose sum is σ = 934267260. Its totient is φ = 622844832.

The previous prime is 778556039. The next prime is 778556059. The reversal of 778556045 is 540655877.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 540655877 = 37 ⋅14612321.

It can be written as a sum of positive squares in 2 ways, for example, as 181144681 + 597411364 = 13459^2 + 24442^2 .

It is a cyclic number.

It is not a de Polignac number, because 778556045 - 2¹⁶ = 778490509 is a prime.

It is a super-2 number, since 2×778556045² = 1212299030412084050, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77855600 + ... + 77855609.

It is an arithmetic number, because the mean of its divisors is an integer number (233566815).

Almost surely, 2^778556045 is an apocalyptic number.

It is an amenable number.

778556045 is a deficient number, since it is larger than the sum of its proper divisors (155711215).

778556045 is a wasteful number, since it uses less digits than its factorization.

778556045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155711214.

The product of its (nonzero) digits is 1176000, while the sum is 47.

The square root of 778556045 is about 27902.6171711544. The cubic root of 778556045 is about 919.9480299093.

The spelling of 778556045 in words is "seven hundred seventy-eight million, five hundred fifty-six thousand, forty-five".